Avionics-Archive.digest.vol-ag

November 28, 2002 - July 08, 2003



      
      
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Date: Nov 28, 2002
From: Matt Dralle <dralle(at)matronics.com>
Subject: New Gift Selection Added - List Fund Raiser! [Please Read]
Dear Listers, I've just added a great new last minute Gift Selection to this year's List Fund Raiser line up! I have a very limited number of sets of a wonderful collection of Aircraft Technical books by Jeppesen entitled "The A&P Technical Series Book Set". This is a great opportunity to make a generous Contribution to support the Lists and walk away with a great set of reference manuals at the same time. This set of books normally retails for over $117 PLUS shipping, but you can pick up your set AND make this year's List Contribution for a cool C-note - that's a $100, by the way! :-) I'm thinking "Great Christmas Gift"... There's more information on the books and making your Contribution at the List Contribution web site: Email List Contribution Web Site: http://www.matronics.com/contribution We're coming close to the official end of this year's List Fund Raiser and if you haven't yet made your Contribution, there's still time get your name on that List of Contributors! The percentage of contributors is kind of low this year but I'm hoping many of you are just holding out until the last minute! I want to thank each and everyone of you that has already made a donation to support the continued operation and upgrade of these List Services. As I've mentioned in the past, running these Lists is a labor of love for me and the hours upon hours of code development, system maintenance, and upgrades are MY Contribution to support this great resource for Builders and Flyer's alike. Won't your take a minute and make YOUR Contribution today? I want to thank you for your support both during the Fund Raiser but also throughout the year in the form of kind words and moral support. A nice comment from a List member about how much the lists have helped them is always a sure way to brighten my day! Thank you to all! Matt Dralle Email List Admin. Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft ________________________________________________________________________________
Date: Nov 28, 2002
From: Matt Dralle <dralle(at)matronics.com>
Subject: [PLEASE READ!] "What is my Contribution used for?"
Dear Listers, Some have asked, "What is my Contribution used for?", and this is a valid question. Here are just a few examples of what your direct List support enables. It provides for the expensive, business-class, high-speed Internet connection used on the List, insuring maximum performance and minimal contention when accessing List services. It pays for the regular system hardware and software upgrades enabling the highest performance possible for services such as the Archive Search Engine and List Browser. It pays for 14+ years worth of online archive data available for instant random access. And, it offsets the many hours spent writing, developing, and maintaining the custom applications that power this List Service such as the List Browse, Search Engine, and Photoshare. But most importantly, your List Contribution enables a forum where you and your peers can communicate freely in an environment that is free from moderation, censorship, advertising, commercialism, SPAM, and computer viruses. How many places on the Internet can you make all those statements about these days? I will venture to say - next to none... It is YOUR CONTRIBUTION that directly enables these many desirable aspects of this most valuable List service. Please support it today with your List Contribution. Its the best investment you can make in your Sport - BAR NONE! Email List Contribution Web Site: http://www.matronics.com/contribution Thank you for your support! Matt Dralle Email List Administrator ________________________________________________________________________________
Date: Nov 30, 2002
From: Matt Dralle <dralle(at)matronics.com>
Subject: List Report...
Dear Listers, This is the last "official" day of the List Fund Raiser. Based on previous year's percentages of Lister's making a Contribution, this year we are nearly 40% behind the normal... And I thought all those great gifts would eke the percentage up past the average a little. Oh well. Maybe people just don't really mind the flashing banner ads for Viagra, and popups for X10 minicams... There's still plenty of time to get your name of the List of Contributors. I'll probably publish the LOC on Monday night after I process the checks from the Post Office. I do want to thank everyone that has so generously made a Contribution so far this year. Your support is greatly appreciated and is what makes the Lists possible. How to support your Lists this month: http://www.matronics.com/contributions Thank you! Matt Dralle Email List Admin. ________________________________________________________________________________
Date: Nov 30, 2002
From: Matt Dralle <dralle(at)matronics.com>
Subject: All New List Digest Format!!
Dear Listers, I've just finished up some awesome code that will completely change your thinking about how email Digests should work and look! Yeah, I'm kind of proud of it, that is true... :-) What you'll be getting in the new List Digest message is the following: The main message will contain the new text-based index I introduced a few weeks back. But here's where things get different... Instead of simply including all of the day's posts in line within the message, there will now be included two enclosures - one with a HTML encoded version of the Digests, and another with the usual text-only version of the Digests. I think you're really going to like the new HTML enclosure of the Digests. All of the Indexes at the top are now hyperlinked to the actual posts and there are hyperlinks at the top of each post that will: o Take you back to the Index o Take you to the next post o Take you to the previous post o Allow you to respond to the LIST regarding the message o Allow you to respond directly to the POSTER regarding the message You'll have to check it out to appreciate the full goodness of the new format! :-) The text-only version is basically exactly the same data that has been normally sent in line within the message. You'll also note that the filenames of the enclosures are such that they can be conveniently placed in a personal "archive" directory for future reference. Hope you enjoy the new Digest format!!! Oh, and don't forget about the Fund Raiser! :-) Matt Dralle Email List Admin. ________________________________________________________________________________
Date: Dec 01, 2002
From: Matt Dralle <dralle(at)matronics.com>
Subject: New, NEW List Digest Format...
Dear Listers, Okay, so I woke up this morning to an email box full of hate-mail about the new List Digest format. I thought it was cool, but I guess not... Still, it seemed like too much code to just throw out, so I've modified things a little and I'm hoping everyone will be happy with the new, NEW arrangement. Here's how it works now: o The HTML and TXT enclosures aren't sent in the Digest any longer. o URL Links to the HTML and TEXT versions of the day's Digests will be found at the top of the digest email. o The new Digest Index will be found at the top of the digest email following the URL Links. o The full digest text will then be found in the email as before. o All of the previous Digests will now be available on line. The URL for the main digest page is: http://www.matronics.com/digest From here, you can drill into the specific List Digest of interest. o Both the HTML and TXT versions of the Digests can be found here. o The List Message Trailer will contain a Link directly to the given o Right now there's only one Digest shown, but each day there will be another. They will be sorted with the newest at the top. Left-hand column is the HTML version, right-hand column the TXT version. A couple people also complained that some messages in the HTML version were just one long line that went off to the right forever and they hated that. Come to think of it, this is also an issue in the Search Engine, List Browser, and Archive Browser. Some email programs don't included hard Returns at regular intervals and that's what causes this. I wrote a program tonight that will automatically chop these long lines into 78 characters or less and wrap the rest of the line. After tonight's Archive transfer, all of the Searching and Browsing tools shouldn't have the problem any longer either. Woo hoo! So, back to the new Digest format. What people are going to see in the new, NEW Digest is a bit of verbiage at the top of the email describing the URL links to the HTML and TXT on-line versions, followed by the Links, followed by the day's Index, followed by the day's messages just as before. Lines longer than 78 characters will also be automatically wrapped onto the next line. Hopefully this will be a more pleasing arrangement for everyone. Sorry to get everybody so stirred up over the format change! The List of Contributors is coming out tomorrow night... Still time to make that Contribution! http://www.matronics.com/contribution Best regards, Matt Dralle Email List Admin. ________________________________________________________________________________
From: "Jeff Green" <jegreen(at)apexmail.com>
Subject: Parts inventory
Date: Dec 03, 2002
I'm looking for recommendations on a program or an Access database that someone has set up to track aircraft parts inventory. I can set up an Access database, but prefer not to reinvent the wheel! Thanks, Jeff ________________________________________________________________________________
Date: Dec 03, 2002
From: Rowland & Wilma Carson <rowil(at)clara.net>
Subject: Re: Parts inventory
>I'm looking for recommendations on a program or an Access database >that someone has set up to track aircraft parts inventory Jeff - have you considered using FileMaker Pro? It has the advantages of being cross-platform, unlike Access, and being easy to learn (unlike ...), and the solutions in FMP are easy to modify to your own requirements ( ...). There is a very active FMP e-mail list where someone has probably done what you want already and would be willing to share or sell a turnkey (or close) solution. Contact me off-list if you want more info. Of course there may also be an Access e-mail list where similar answers may be found - I just don't know of it since I don't have to use Access in anger (although I have sat by other folk and monitored their sweat with it). regards Rowland | Wilma & Rowland Carson <http://home.clara.net/rowil/> | ... that's Rowland with a 'w' ... ________________________________________________________________________________
From: ROBINFLY(at)aol.com
Date: Dec 09, 2002
Subject: re: questions on antennas
I always have one com that is stronger than the other. While I have the floor board removed (these are bottom mounted antennas), I decided to check the contact between the antennas and the skin. I found the weak com's antenna cable was shorted in the connector (so much for the $2K installation labor for one GPS/Com w/ new antenna & calbe I paid 2 years ago). I did not remove the antennas, but "ohm" the antenna connectors' shield (ground?) and A/C skin and both read .2 ohm. I also found that when I "ohm" the coax connectors on both antenna (not on cable), the weak com antenna has no connection between the center and shield (ground?) but the good com antenna reads .4 ohm between the center and shield. Does it sound right? If the good com antenna and the A/C ground are connected (w/ .4 ohm), how can it be the "good" com antenna? Robin Hou E35 Bo, N7303B ________________________________________________________________________________
From: "Dennis O'Connor" <doconnor(at)chartermi.net>
Subject: Re: re: questions on antennas
Date: Dec 09, 2002
this is a topic that could become a text book... First, I suggest that you interchange the antennas to the radios... Move the weak antenna/coax to the strong com, and the strong antenna/coax to the weak com and see if anything changes... Report back and we can discuss it..And yes, both antennas could be fine even though one shows an open connection for DC and the other shows. 0.4 ohms due to different internal construction... Denny ----- Original Message ----- From: <ROBINFLY(at)aol.com> Subject: Avionics-List: re: questions on antennas > > I always have one com that is stronger than the other. While I have the > floor board removed (these are bottom mounted antennas), I decided to check > the contact between the antennas and the skin. I found the weak com's > antenna cable was shorted in the connector (so much for the $2K installation > labor for one GPS/Com w/ new antenna & calbe I paid 2 years ago). I did not > remove the antennas, but "ohm" the antenna connectors' shield (ground?) and > A/C skin and both read .2 ohm. > > I also found that when I "ohm" the coax connectors on both antenna (not on > cable), the weak com antenna has no connection between the center and shield > (ground?) but the good com antenna reads .4 ohm between the center and > shield. Does it sound right? If the good com antenna and the A/C ground are > connected (w/ .4 ohm), how can it be the "good" com antenna? > > Robin Hou > E35 Bo, > N7303B > > ________________________________________________________________________________
From: Benford2(at)aol.com
Date: Jan 07, 2003
Subject: Intercom wiring ???
I bought a PS Engineering PM 1000ll and went to install it,and low and behold there where no schematics in the box. So I called them and they said " take it to an avionics shop" and then he told me that there is no warrenty on their unit unless I bought a harness from them for 200.00$. My question is this,,,, Mark at PS Engineering told me their units need shielded wires on ALL runs, even the PTT circuit. Either their intercoms are poorly designed or he is trying to con people into buying a harness from him. Has anyone out there installed this model with shielded wire on the mic circuit and regular 20 ga tefzel wires on all others?? Did it work ok??? Thanks in advance. Ben Haas N801BH. ________________________________________________________________________________
Date: Jan 07, 2003
From: Gary Liming <gary(at)liming.org>
Subject: Re: Intercom wiring ???
Ben, The PTT circuit only grounds the mike key, so there is absolutely no reason to shield it (although it wouldn't hurt if you did.) The instructions for my intercom calls for shielded wire for the line for the mike and headphone jack wiring for each seat, and for each line to/from any other audio signal (like music, ADF, NAV, etc.) Gary > >I bought a PS Engineering PM 1000ll and went to install it,and low and behold >there where no schematics in the box. So I called them and they said " take >it to an avionics shop" and then he told me that there is no warrenty on >their unit unless I bought a harness from them for 200.00$. My question is >this,,,, Mark at PS Engineering told me their units need shielded wires on >ALL runs, even the PTT circuit. Either their intercoms are poorly designed or >he is trying to con people into buying a harness from him. Has anyone out >there installed this model with shielded wire on the mic circuit and regular >20 ga tefzel wires on all others?? Did it work ok??? Thanks in advance. Ben >Haas N801BH. > > ________________________________________________________________________________
Date: Jan 07, 2003
From: "Gary Kozinski" <KOZINSKI(at)symbol.com>
Subject: Re: Intercom wiring ???
Go the the PS Engineering web site. www.ps-engineering.com All the schematics are there. I have a PS501 and got the drawings off their site. Everything works fine. Made my own harness using shielded wire. You might think twice about buying a prebuild harness unless you have expert wiring technique. You'll spend have the cost for connectors and wire then 2-6 hours making the harness. Be sure to ground only one end. Of course the warrenty will be voided if you botch things up. Be then I believe they have a cheep flat rate fix it cost of like $50 if anything ever goes wrong. Good luck. Gary >>> Benford2(at)aol.com 01/07/03 09:48AM >>> I bought a PS Engineering PM 1000ll and went to install it,and low and behold there where no schematics in the box. So I called them and they said " take it to an avionics shop" and then he told me that there is no warrenty on their unit unless I bought a harness from them for 200.00$. My question is this,,,, Mark at PS Engineering told me their units need shielded wires on ALL runs, even the PTT circuit. Either their intercoms are poorly designed or he is trying to con people into buying a harness from him. Has anyone out there installed this model with shielded wire on the mic circuit and regular 20 ga tefzel wires on all others?? Did it work ok??? Thanks in advance. Ben Haas N801BH. This email has been scanned for computer viruses. ________________________________________________________________________________
Date: Jan 14, 2003
From: "sptom(at)cts.com" <sptom(at)cts.com>
Subject: Socket Extractor
A simple question (I hope). I have a broken wire on the female (socket) side of a D-Sub miniature (high-density) connector that connects my radio (KY97A) to my intercom (NAT 83-001). Is there an extraction tool that can be used on these very fine sockets. If so, what is the tool name (number) and where do I get one. If not, what do I do, start over with a new connector? Thanks! Tom ________________________________________________________________________________
Date: Jan 14, 2003
From: David Aronson <aronsond(at)pacbell.net>
Subject: Re: Socket Extractor
Radio Shack has them. Just look for D-sub connector remover. They have both miniature and regular. David Aronson RV4 N504RV ----- Original Message ----- From: <sptom(at)cts.com> Subject: Avionics-List: Socket Extractor > > A simple question (I hope). I have a broken wire on the female (socket) > side of a D-Sub miniature (high-density) connector that connects my radio > (KY97A) to my intercom (NAT 83-001). Is there an extraction tool that can > be used on these very fine sockets. If so, what is the tool name (number) > and where do I get one. If not, what do I do, start over with a new > connector? Thanks! > > Tom > > ________________________________________________________________________________
Date: Jan 18, 2003
From: Tom Brusehaver <cozytom(at)mn.rr.com>
Subject: Air Data Compter
I am building something like the airdata computer that was in the December Circuit Cellar magazine. I was kind disappointed in the article, there was no code, only snippets of schematics, and fomulas with no units, but it was enough to get me started. I started using a HandyBoard, but it only has 8 bit A/D convertors in it, so I couldn't get the resolution I needed. Looking around for other A/D convertors, I found the Dallas DS2438 one wire A/D (battery monitor), and I have had a TINI gathering dust for about two years, so I thought it would be perfect! I found David Bray's One Wire Barometer page, and thought I'd steal parts of his amplifyer to make this more useful. So I was looking for stuff about connecting LCDs to the TINI board, and google finds this Avionics-Archive from a June 2000-March 2001 where folks were talking about TINI and airplanes, and I felt I needed to subscribe. When I looked further I realized I WAS subscribed to the list. Are folks still building stuff? I am kinda jazzed about one-wire in airplanes, since it seems like a really easy way to build modular things, and using the Tini as the central controller, send information to various PDAs and other displays. I have 2 modules in mind at the moment, the airdata, and maybe if I can get it working an AOA meter. I could see engine monitors, and general purpose sensor packages, including fuel, landing gear, etc. If I am wacko, just delete this message, and I'll go away. Tom ________________________________________________________________________________
From: "Matthew Mucker" <matthew(at)mucker.net>
Subject: Air Data Compter
Date: Jan 18, 2003
I'm not too thrilled about one-wire; the software overhead is pretty steep. But I definitely like the embedded micro stuff in airplanes! The thing is that most of the "gee I wish" items that we were dreaming of 2 years ago are starting to hit the market. Why do it myself when I can buy Blue Mountain's complete EFIS system? Having said that, I'm sure the bug to solder will bite me again soon, and I'm sure you'll find an eager audience here for your projects! -Matt Oh yeah: you're no more wacko than the rest of us! > Are folks still building stuff? I am kinda jazzed about > one-wire in airplanes, since it seems like a really easy > way to build modular things, and using the Tini as the > central controller, send information to various PDAs and > other displays. > > I have 2 modules in mind at the moment, the airdata, and > maybe if I can get it working an AOA meter. I could see > engine monitors, and general purpose sensor packages, > including fuel, landing gear, etc. > > If I am wacko, just delete this message, and I'll go away. ________________________________________________________________________________
Date: Jan 18, 2003
From: Tim & Diane Shankland <tshank(at)megsinet.net>
Subject: Coolent flow
I am presently designing a cooling system for my Stratus. I plan to have the radiators inside the cowling. In order not to have to do rework after building I am first characterizing various radiators in order to be sure they are capable of cooling the engine. There is one piece of information I still need. Does anyone know the coolant flow rate of the Status suburu at full power? I need an idea of how many gallons per minute will be going through the cooling system. When I get all the math done I will be happy to share it with anyone else trying this. Tim Shankland ________________________________________________________________________________
Date: Jan 18, 2003
From: "Jim V. Wickert" <JimW_btg(at)compuserve.com>
Subject: Air Data Compter
Tom, I do a great bit of Industrial Automation and Process control which requires precision A to D conversion for critical silicon wafer processing control, but on an airplane what is wrong with 8bit? Many process control situations with critical process interjection of change are using 12 bit algorithms, very seldom do you see 16 bit,..... why, process conversion time. For an oil, head, water or any other converstion, 8 bit is quite adequate. A typical 8 bit conversion for a single channel will take about 4 to6 Mil sec. for a 11 to 12 bit you are looking at 10 to 14 Mil Sec. for a 16 bit converstion you maybe looking at 18 to 21 Mil sec this all depends on the processor I know but what precision are you showing on the display whole numbers we do not need 16 bit precision and the lag in most of the Engine Information Systems is much slower that the update of the 16 bit precesor as well?? We do not need to kill ourselves with A to D conversion algorithm software development in something like C++ or Vicual C when we have at best 10 channels of 8 bit conversions. We are better off developing intuitive diagnostics that tracks history and control levels and will monitor other critical functions of the operating system that will indicate a problem before it hapens if we want to labor with software development. Just some simple thought process as this same ideal model has reduced cost and improved production and quality for Intel Semiconductor production. Jim Wickert Vision #159 ________________________________________________________________________________
From: "Werner Schneider" <WernerSchneider(at)compuserve.com>
Subject: Re: Air Data Compter
Date: Jan 19, 2003
Tom, you might have more luck in the aerolectrics list werner (using RKM and a memory module for the task) ----- Original Message ----- From: "Tom Brusehaver" <cozytom(at)mn.rr.com> Subject: Avionics-List: Air Data Compter > > > I am building something like the airdata computer that was in the > December Circuit Cellar magazine. I was kind disappointed in the > article, there was no code, only snippets of schematics, and > fomulas with no units, but it was enough to get me started. > > I started using a HandyBoard, but it only has 8 bit A/D > convertors in it, so I couldn't get the resolution I needed. > Looking around for other A/D convertors, I found the Dallas > DS2438 one wire A/D (battery monitor), and I have had a > TINI gathering dust for about two years, so I thought it > would be perfect! > > I found David Bray's One Wire Barometer page, and thought > I'd steal parts of his amplifyer to make this more useful. > > So I was looking for stuff about connecting LCDs to the > TINI board, and google finds this Avionics-Archive from a > June 2000-March 2001 where folks were talking about TINI > and airplanes, and I felt I needed to subscribe. When I > looked further I realized I WAS subscribed to the list. > > Are folks still building stuff? I am kinda jazzed about > one-wire in airplanes, since it seems like a really easy > way to build modular things, and using the Tini as the > central controller, send information to various PDAs and > other displays. > > I have 2 modules in mind at the moment, the airdata, and > maybe if I can get it working an AOA meter. I could see > engine monitors, and general purpose sensor packages, > including fuel, landing gear, etc. > > If I am wacko, just delete this message, and I'll go away. > > Tom > > > > > > ________________________________________________________________________________
Date: Jan 19, 2003
From: Tony Cann <tony.cann(at)sun.com>
Subject: Re: Air Data Compter
Thanks for the discussion on 8 bit vs 12 bit. A couple of questions: - are there any places on an aircraft where we do need 12 bits? -- fuel quantity? -- fuel flow? - what do you think of multiplexing things like 6 EGT probes into one A/D? Are there accuracy or response time problems when you are leaning? Tony > From: "Jim V. Wickert" <JimW_btg(at)compuserve.com> > Subject: Avionics-List: Air Data Compter > > > Tom, > > I do a great bit of Industrial Automation and Process control which > requires precision A to D conversion for critical silicon wafer processing > control, but on an airplane what is wrong with 8bit? Many process control > situations with critical process interjection of change are using 12 bit > algorithms, very seldom do you see 16 bit,..... why, process conversion > time. For an oil, head, water or any other converstion, 8 bit is quite > adequate. A typical 8 bit conversion for a single channel will take about > 4 to6 Mil sec. for a 11 to 12 bit you are looking at 10 to 14 Mil Sec. for > a 16 bit converstion you maybe looking at 18 to 21 Mil sec this all depends > on the processor I know but what precision are you showing on the display > whole numbers we do not need 16 bit precision and the lag in most of the > Engine Information Systems is much slower that the update of the 16 bit > precesor as well?? > > We do not need to kill ourselves with A to D conversion algorithm software > development in something like C++ or Vicual C when we have at best 10 > channels of 8 bit conversions. We are better off developing intuitive > diagnostics that tracks history and control levels and will monitor other > critical functions of the operating system that will indicate a problem > before it hapens if we want to labor with software development. > > Just some simple thought process as this same ideal model has reduced cost > and improved production and quality for Intel Semiconductor production. > > Jim Wickert > Vision #159 ________________________________________________________________________________
Date: Jan 19, 2003
From: Tom Brusehaver <cozytom(at)mn.rr.com>
Subject: Re: Air Data Compter
Cool, you folks don't think I am a nut :-). When I plug the MPX4115 directly into the 8 bit A/D converter, the resolution was only about .17 inches of mercury. (ATIS says altimeter 30.02, I can enter 29.97 or 30.14, I thought I could do better). So that is why I am looking at the amplifyer, to move the usable range of the sensor into the ball park of the A/D converter. Using a serial A/D converter pretty much throws out the speed question anyway. It takes longer to clock the data in than convert it :-). The DS2438 has two A/D channels, so I think it is a fine choice for the air data comuter. I am only trying to measure altitude, and airspeed (and temprature). Rate of change of these items is pretty slow, sampling 10 times a second would probably be good enough, but I'll go as fast as possible. Jim V. Wickert wrote: > > Tom, > > I do a great bit of Industrial Automation and Process control which > requires precision A to D conversion for critical silicon wafer processing > control, but on an airplane what is wrong with 8bit? ________________________________________________________________________________
Date: Jan 19, 2003
From: Rowland & Wilma Carson <rowil(at)clara.net>
Subject: Re: Coolent flow
>Avionics-List message >Does anyone know the coolant flow rate of the >Status suburu Tim - isn't there a Subaru list where you'd have a better chance of an informed answer? I'd be worthwhile checking the selection hosted by Matronics or maybe those available on Yahoo groups. Come to that, can't the Subaru aero-conversion engine suppliers give you this sort of information? It's certainly important; I know many early adopters of the Subaru in the Europa had cooling problems - although those may have been caused by airflow rather than liquid coolant flow restrictions. regards Rowland | Rowland Carson Europa Club Membership Secretary | Europa 435 G-ROWI (450 hours building) PFA #16532 EAA #168386 | e-mail website ________________________________________________________________________________
Date: Jan 20, 2003
From: Bruce Boyes <bboyes(at)systronix.com>
Subject: Re: Air Data Computer
> >Thanks for the discussion on 8 bit vs 12 bit. A couple of questions: >- are there any places on an aircraft where we do need 12 bits? > -- fuel quantity? > -- fuel flow? >- what do you think of multiplexing things like 6 EGT probes > into one A/D? Are there accuracy or response time problems when > you are leaning? > >Tony Given that 8 bits resolves better than 1/2 of 1%, I don't think my eyeball can detect that much on an analog EGT or any other gauge. The trick is applying that 8 bits to the region of interest, say 900-1400 F for EGT, that would be a resolution of 2 degrees. 0-1400F is about 6 degrees, still probably plenty. We often use 12-bit converters because they are cheap and available, and discard the low two bits or average the data so that we get 10 bits or so effective resolution. If you get an EGT update more than say twice per second while leaning that's probably fast enough. The thermocouple is not instantaneous, anyway. That would be the limiting factor - the probe's rate of change. Similar issues on other parameters - let the resolution of the sensor drive the ADC design. I don't have a clue what fuel flow gauges can resolve but I bet someone on the list does. Bruce Boyes ________________________________________________________________________________
Date: Jan 20, 2003
From: Bruce Boyes <bboyes(at)systronix.com>
Subject: Re: Air Data Computer
> > >I am building something like the airdata computer that was in the >December Circuit Cellar magazine. I was kind disappointed in the >article, there was no code, only snippets of schematics, and >fomulas with no units, but it was enough to get me started. > >I started using a HandyBoard, but it only has 8 bit A/D >convertors in it, so I couldn't get the resolution I needed. >Looking around for other A/D convertors, I found the Dallas >DS2438 one wire A/D (battery monitor), and I have had a >TINI gathering dust for about two years, so I thought it >would be perfect! I'm a big fan of TINI, in fact we will soon be manufacturing them ourselves: www.tstik.com However, the tool should always fit the job. 1Wire does not do well in electrically noisy environments, so I'm not sure how well it would do in an aircraft with the ignition system and multiple radio transmitters. I've wondered about CAN net - which TINI also supports - CAN is designed for noisy environments, and is in fact being used in air- and water- target drones by the US military. It's also used in mission critical car, truck, and bus applications. Cygnal systems now has some low cost 8051 nodes with 12-bit ADC, PGA, and -- CAN. So use those as the sensor nodes and tie them back to something like TINI for monitoring, display and logging. An iButton device would make a dandy ignition lock / security system, too. Might be a great thing for clubs, etc. An electronic log of who flew when. Bruce Boyes ________________________________________________________________________________
Date: Jan 21, 2003
From: Tom Brusehaver <cozytom(at)mn.rr.com>
Subject: Re: Air Data Computer
> > I'm a big fan of TINI, in fact we will soon be manufacturing them > ourselves: www.tstik.com I think it was one of your posts that hooked me in this discussion :-). Archives man! > However, the tool should always fit the job. 1Wire does not do well in > electrically noisy environments, so I'm not sure how well it would do in an > aircraft with the ignition system and multiple radio transmitters. That will something to watch, thanks for the input. I have played a little with one wire, nothing too long tho, it seems reliable around amateur radio equipment. > I've wondered about CAN net - which TINI also supports - CAN is designed > for noisy environments, and is in fact being used in air- and water- target > drones by the US military. It's also used in mission critical car, truck, > and bus applications. If there were more CAN peripherials, for now, I think it'd be CPU->CAN->CPU. Nothing wrong with, for big stuff. > An iButton device would make a dandy ignition lock / security system, too. > Might be a great thing for clubs, etc. An electronic log of who flew when. I had thought of that, but feared I'd loose the iButton, and I wouldn't be smart enough to putsome override in :-) I think tho, I might use one for data logging. I have a couple of the 64Kbit ones. Not a lot of data, but it'd be handy. (Probably one of those USB drives would be more convenient). ________________________________________________________________________________
From: "Herb Watson" <wraithe2(at)tds.net>
Subject: Arnav R-21 LORAN
Date: Jan 22, 2003
Herb Watson Wraithe2(at)tds.net Hello, I'm looking for an operators manual, and wiring harness for the Arnav R-21 LORAN. Anyone got any ideas? Thanks in advance. Herb ________________________________________________________________________________
From: "PAUL RIVERS" <creekcarp(at)worldnet.att.net>
Subject: gears for narco com's
Date: Jan 23, 2003
does anyone know where to get the plastic gears for Narco com's---tnx Paul ________________________________________________________________________________
From: RFG842(at)aol.com
Date: Jan 24, 2003
Subject: Low voltage
Not really an avionics problem but close. Member of the KRnet is looking for a circuit to add a low voltage indicator lite for for his battery driven ignition system on his Volks engine. Would be able to tell if his alternator was working at a glance. Thanks, Bob ________________________________________________________________________________
Date: Jan 24, 2003
From: Hal Rozema <hartist1(at)cox.net>
business journal , CHANNEL 3 , Chuck Mulloy , drudge , George W Bush , Joe Norris EAA Information , Mariann , Mike DiFrisco , Paul Bessing kitlog , to send to Jodel Group , ZENITH LIST , "rv-list(at)matronics.com" , "avionics-list(at)matronics.com"
Subject: Be Aware FAA can pull anyones license without recourse..
SECURITY You're Grounded/Suspended: TSA Trumps FAA TSA Takes Over Issuance/Maintenance of Certificates, in New NPRM In the Federal Register Friday, 01.24.2003, you'll be able to see that you can be knocked out of the air -- just like that -- if the TSA alleges that you pose a 'security risk.' Pilots will be immediately grounded; mechanics, DERs -- everybody who holds a certificate of any kind from the FAA -- can be immediately out of a job. The TSA will notify you that you are considered a 'security risk.' It will notify the FAA; and the FAA will immediately suspend your ticket(s), pending your 'appeal.' You will then have to convince the TSA (which already declared you a 'security risk') that you are not a 'security risk,' without your knowing why they think you are such a risk. Then, when the TSA issues its final ruling, the FAA will revoke your papers. We wanted some confirmation on this, and called the TSA. Chris Rhatigan, in the press office there, said, "You may have to talk to the FAA on that." We read her a part of the summary, which says, "This final rule expressly makes a person ineligible to hold FAA-issued airman certificates if the Transportation Security Administration notifies the FAA in writing that the person poses a security threat." As we continued reading, and noted that the TSA was calling the shots, she said, "Hold on a second." She returned, and said, "This [determination that you're a security threat] comes from an intelligence database." OK -- so, how do we know how big a threat, or how it's determined that one even is such a threat? "We don't tell people how to get on to that database," she said. In other words, if you're denied your certificate, you won't be able to find out why -- just that someone, somewhere, thinks you're a 'security risk.' Ms Rhatigan informed us that everything would be spelled out in the NPRM, and that we'd have to wait until Friday, to see what was getting published in the Federal Register. Well, folks the law goes into effect Friday. No NPRM. No discussion. Decree. Tough. ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: Be Aware FAA can pull anyones license without recourse..
SECURITY
Date: Jan 24, 2003
I was able to make an electronic comment on the NPRM 2003-14293. I thought maybe some of the rest of you might have a need to do this at some time so here are my instructions and suggestions. 1. Start at http://www.archives.gov/federal_register/index.html Here is where you can navigate to the register and find the notices for your comments. I found that I wanted to comment on 2003-14293 Ineligibility for an Airman Certificate Based on Security Grounds 2. I then went to: http://dms.dot.gov and clicked on the "comment/submissions" tab. You can also do a search at this point. 3. I clicked continue on the next page. 4. After entering the docket number, it took me to the comment page. It is probably best to enter in your personal data but it doesn't not seem to be required. 5.Enter you comment in the box and click on submit. That's all. 6. You can copy and paste in your comments so I composed and Spell Checked it in Outlook Express but you could do the same copy and paste from a word processor. I need this to make me look intelligent. Cy Galley Editor, EAA Safety Programs cgalley(at)qcbc.org or experimenter(at)eaa.org ----- Original Message ----- From: "Hal Rozema" <hartist1(at)cox.net> "business journal" ; "CHANNEL 3" ; "Chuck Mulloy" ; "drudge" ; "George W Bush" ; "Joe Norris EAA Information" ; "Mariann" ; "Mike DiFrisco" ; "Paul Bessing kitlog" ; "to send to Jodel Group" ; "ZENITH LIST" ; ; Subject: Avionics-List: Be Aware FAA can pull anyones license without recourse.. SECURITY > > > You're Grounded/Suspended: TSA Trumps FAA > TSA Takes Over Issuance/Maintenance of Certificates, in New NPRM > > In the Federal Register Friday, 01.24.2003, you'll be able to see that > you can be > knocked out of the air -- just like that -- if the TSA alleges that you > pose > a 'security risk.' Pilots will be immediately grounded; mechanics, DERs > -- > everybody who holds a certificate of any kind from the FAA -- can be > immediately out of a job. > > The TSA will notify you that you are considered a 'security risk.' It > will > notify the FAA; and the FAA will immediately suspend your ticket(s), > pending > your 'appeal.' > > You will then have to convince the TSA (which already declared you a > 'security risk') that you are not a 'security risk,' without your > knowing > why they think you are such a risk. Then, when the TSA issues its final > ruling, the FAA will revoke your papers. > > We wanted some confirmation on this, and called the TSA. Chris Rhatigan, > in > the press office there, said, "You may have to talk to the FAA on that." > > We read her a part of the summary, which says, "This final rule > expressly > makes a person ineligible to hold FAA-issued airman certificates if the > Transportation Security Administration notifies the FAA in writing that > the > person poses a security threat." > > As we continued reading, and noted that the TSA was calling the shots, > she > said, "Hold on a second." She returned, and said, "This [determination > that > you're a security threat] comes from an intelligence database." OK -- > so, > how do we know how big a threat, or how it's determined that one even is > > such a threat? "We don't tell people how to get on to that database," > she > said. In other words, if you're denied your certificate, you won't be > able > to find out why -- just that someone, somewhere, thinks you're a > 'security > risk.' > > Ms Rhatigan informed us that everything would be spelled out in the > NPRM, > and that we'd have to wait until Friday, to see what was getting > published > in the Federal Register. Well, folks the law goes into effect Friday. No > > NPRM. No discussion. Decree. Tough. > > ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: Be Aware FAA can pull anyones license without recourse..
SECURITY
Date: Jan 24, 2003
I was able to make an electronic comment on the NPRM 2003-14293. I thought maybe some of the rest of you might have a need to do this at some time so here are my instructions and suggestions. 1. Start at http://www.archives.gov/federal_register/index.html Here is where you can navigate to the register and find the notices for your comments. I found that I wanted to comment on 2003-14293 Ineligibility for an Airman Certificate Based on Security Grounds 2. I then went to: http://dms.dot.gov and clicked on the "comment/submissions" tab. You can also do a search at this point. 3. I clicked continue on the next page. 4. After entering the docket number, it took me to the comment page. It is probably best to enter in your personal data but it doesn't not seem to be required. 5.Enter you comment in the box and click on submit. That's all. 6. You can copy and paste in your comments so I composed and Spell Checked it in Outlook Express but you could do the same copy and paste from a word processor. I need this to make me look intelligent. Cy Galley Editor, EAA Safety Programs cgalley(at)qcbc.org or experimenter(at)eaa.org ----- Original Message ----- From: "Hal Rozema" <hartist1(at)cox.net> "business journal" ; "CHANNEL 3" ; "Chuck Mulloy" ; "drudge" ; "George W Bush" ; "Joe Norris EAA Information" ; "Mariann" ; "Mike DiFrisco" ; "Paul Bessing kitlog" ; "to send to Jodel Group" ; "ZENITH LIST" ; ; Subject: Avionics-List: Be Aware FAA can pull anyones license without recourse.. SECURITY > > > You're Grounded/Suspended: TSA Trumps FAA > TSA Takes Over Issuance/Maintenance of Certificates, in New NPRM > > In the Federal Register Friday, 01.24.2003, you'll be able to see that > you can be > knocked out of the air -- just like that -- if the TSA alleges that you > pose > a 'security risk.' Pilots will be immediately grounded; mechanics, DERs > -- > everybody who holds a certificate of any kind from the FAA -- can be > immediately out of a job. > > The TSA will notify you that you are considered a 'security risk.' It > will > notify the FAA; and the FAA will immediately suspend your ticket(s), > pending > your 'appeal.' > > You will then have to convince the TSA (which already declared you a > 'security risk') that you are not a 'security risk,' without your > knowing > why they think you are such a risk. Then, when the TSA issues its final > ruling, the FAA will revoke your papers. > > We wanted some confirmation on this, and called the TSA. Chris Rhatigan, > in > the press office there, said, "You may have to talk to the FAA on that." > > We read her a part of the summary, which says, "This final rule > expressly > makes a person ineligible to hold FAA-issued airman certificates if the > Transportation Security Administration notifies the FAA in writing that > the > person poses a security threat." > > As we continued reading, and noted that the TSA was calling the shots, > she > said, "Hold on a second." She returned, and said, "This [determination > that > you're a security threat] comes from an intelligence database." OK -- > so, > how do we know how big a threat, or how it's determined that one even is > > such a threat? "We don't tell people how to get on to that database," > she > said. In other words, if you're denied your certificate, you won't be > able > to find out why -- just that someone, somewhere, thinks you're a > 'security > risk.' > > Ms Rhatigan informed us that everything would be spelled out in the > NPRM, > and that we'd have to wait until Friday, to see what was getting > published > in the Federal Register. Well, folks the law goes into effect Friday. No > > NPRM. No discussion. Decree. Tough. > > ________________________________________________________________________________
From: "Fabian Osterwalder" <mail(at)osterwalder.net>
Subject: Be Aware FAA can pull anyones license without recourse..
SECURITY
Date: Jan 24, 2003
That's the way things were done a decade ago in Soviet dominated Eastern Europe..... Fabian (Berlin/Germany) -----Original Message----- From: owner-avionics-list-server(at)matronics.com [mailto:owner-avionics-list-server(at)matronics.com]On Behalf Of Cy Galley Subject: Re: Avionics-List: Be Aware FAA can pull anyones license without recourse.. SECURITY I was able to make an electronic comment on the NPRM 2003-14293. I thought maybe some of the rest of you might have a need to do this at some time so here are my instructions and suggestions. 1. Start at http://www.archives.gov/federal_register/index.html Here is where you can navigate to the register and find the notices for your comments. I found that I wanted to comment on 2003-14293 Ineligibility for an Airman Certificate Based on Security Grounds 2. I then went to: http://dms.dot.gov and clicked on the "comment/submissions" tab. You can also do a search at this point. 3. I clicked continue on the next page. 4. After entering the docket number, it took me to the comment page. It is probably best to enter in your personal data but it doesn't not seem to be required. 5.Enter you comment in the box and click on submit. That's all. 6. You can copy and paste in your comments so I composed and Spell Checked it in Outlook Express but you could do the same copy and paste from a word processor. I need this to make me look intelligent. Cy Galley Editor, EAA Safety Programs cgalley(at)qcbc.org or experimenter(at)eaa.org ----- Original Message ----- From: "Hal Rozema" <hartist1(at)cox.net> "business journal" ; "CHANNEL 3" ; "Chuck Mulloy" ; "drudge" ; "George W Bush" ; "Joe Norris EAA Information" ; "Mariann" ; "Mike DiFrisco" ; "Paul Bessing kitlog" ; "to send to Jodel Group" ; "ZENITH LIST" ; ; Subject: Avionics-List: Be Aware FAA can pull anyones license without recourse.. SECURITY > > > You're Grounded/Suspended: TSA Trumps FAA > TSA Takes Over Issuance/Maintenance of Certificates, in New NPRM > > In the Federal Register Friday, 01.24.2003, you'll be able to see that > you can be > knocked out of the air -- just like that -- if the TSA alleges that you > pose > a 'security risk.' Pilots will be immediately grounded; mechanics, DERs > -- > everybody who holds a certificate of any kind from the FAA -- can be > immediately out of a job. > > The TSA will notify you that you are considered a 'security risk.' It > will > notify the FAA; and the FAA will immediately suspend your ticket(s), > pending > your 'appeal.' > > You will then have to convince the TSA (which already declared you a > 'security risk') that you are not a 'security risk,' without your > knowing > why they think you are such a risk. Then, when the TSA issues its final > ruling, the FAA will revoke your papers. > > We wanted some confirmation on this, and called the TSA. Chris Rhatigan, > in > the press office there, said, "You may have to talk to the FAA on that." > > We read her a part of the summary, which says, "This final rule > expressly > makes a person ineligible to hold FAA-issued airman certificates if the > Transportation Security Administration notifies the FAA in writing that > the > person poses a security threat." > > As we continued reading, and noted that the TSA was calling the shots, > she > said, "Hold on a second." She returned, and said, "This [determination > that > you're a security threat] comes from an intelligence database." OK -- > so, > how do we know how big a threat, or how it's determined that one even is > > such a threat? "We don't tell people how to get on to that database," > she > said. In other words, if you're denied your certificate, you won't be > able > to find out why -- just that someone, somewhere, thinks you're a > 'security > risk.' > > Ms Rhatigan informed us that everything would be spelled out in the > NPRM, > and that we'd have to wait until Friday, to see what was getting > published > in the Federal Register. Well, folks the law goes into effect Friday. No > > NPRM. No discussion. Decree. Tough. > > ________________________________________________________________________________
Date: Jan 24, 2003
From: Charlie & Tupper England <cengland(at)netdoor.com>
Subject: Re: gears for narco com's
PAUL RIVERS wrote: > >does anyone know where to get the plastic gears for Narco com's---tnx Paul > > > If you find some, please let all of us know. Charlie ________________________________________________________________________________
From: "Jim & Jeanette Oberst" <joberst@cox-internet.com>
Subject: Re: Be Aware FAA can pull anyones license without recourse..
SECURITY
Date: Jan 24, 2003
Thanks. This was really helpful. I hope EVERYONE on this list submits a comment. Jim Oberst. ----- Original Message ----- From: "Cy Galley" <cgalley(at)qcbc.org> Subject: Re: Avionics-List: Be Aware FAA can pull anyones license without recourse.. SECURITY > > I was able to make an electronic comment on the NPRM 2003-14293. I thought > maybe some of the rest of you might have a need to do this at some time so > here are my instructions and suggestions. > 1. Start at http://www.archives.gov/federal_register/index.html > Here is where you can navigate to the register and find the notices for your > comments. > I found that I wanted to comment on 2003-14293 Ineligibility for an Airman > Certificate Based on Security Grounds > 2. I then went to: http://dms.dot.gov > and clicked on the "comment/submissions" tab. You can also do a search at > this point. > 3. I clicked continue on the next page. > 4. After entering the docket number, it took me to the comment page. It is > probably best to enter in your personal data but it doesn't not seem to be > required. > 5.Enter you comment in the box and click on submit. That's all. > 6. You can copy and paste in your comments so I composed and Spell Checked > it in Outlook Express but you could do the same copy and paste from a word > processor. I need this to make me look intelligent. > > Cy Galley > Editor, EAA Safety Programs > cgalley(at)qcbc.org or experimenter(at)eaa.org > > > ----- Original Message ----- > From: "Hal Rozema" <hartist1(at)cox.net> > To: "Geoff" ; "Bill O'Reilly" ; > "business journal" ; "CHANNEL 3" > ; "Chuck Mulloy" ; "drudge" > ; "George W Bush" ; "Joe > Norris EAA Information" ; "Mariann" > ; "Mike DiFrisco" ; "Paul > Bessing kitlog" ; "to send to Jodel Group" > ; "ZENITH LIST" ; > ; > Subject: Avionics-List: Be Aware FAA can pull anyones license without > recourse.. SECURITY > > > > > > > > You're Grounded/Suspended: TSA Trumps FAA > > TSA Takes Over Issuance/Maintenance of Certificates, in New NPRM > > > > In the Federal Register Friday, 01.24.2003, you'll be able to see that > > you can be > > knocked out of the air -- just like that -- if the TSA alleges that you > > pose > > a 'security risk.' Pilots will be immediately grounded; mechanics, DERs > > -- > > everybody who holds a certificate of any kind from the FAA -- can be > > immediately out of a job. > > > > The TSA will notify you that you are considered a 'security risk.' It > > will > > notify the FAA; and the FAA will immediately suspend your ticket(s), > > pending > > your 'appeal.' > > > > You will then have to convince the TSA (which already declared you a > > 'security risk') that you are not a 'security risk,' without your > > knowing > > why they think you are such a risk. Then, when the TSA issues its final > > ruling, the FAA will revoke your papers. > > > > We wanted some confirmation on this, and called the TSA. Chris Rhatigan, > > in > > the press office there, said, "You may have to talk to the FAA on that." > > > > We read her a part of the summary, which says, "This final rule > > expressly > > makes a person ineligible to hold FAA-issued airman certificates if the > > Transportation Security Administration notifies the FAA in writing that > > the > > person poses a security threat." > > > > As we continued reading, and noted that the TSA was calling the shots, > > she > > said, "Hold on a second." She returned, and said, "This [determination > > that > > you're a security threat] comes from an intelligence database." OK -- > > so, > > how do we know how big a threat, or how it's determined that one even is > > > > such a threat? "We don't tell people how to get on to that database," > > she > > said. In other words, if you're denied your certificate, you won't be > > able > > to find out why -- just that someone, somewhere, thinks you're a > > 'security > > risk.' > > > > Ms Rhatigan informed us that everything would be spelled out in the > > NPRM, > > and that we'd have to wait until Friday, to see what was getting > > published > > in the Federal Register. Well, folks the law goes into effect Friday. No > > > > NPRM. No discussion. Decree. Tough. > > > > > > ________________________________________________________________________________
From: "Lynn Manhart" <twomdata(at)connect2.com>
Subject: GPS Interference from Comms
Date: Feb 23, 2003
Does anyone monitoring this list have any experience with eliminating interference from the comms for an IFR certified GPS? I have a Mooney with a KX-155 comm/nav and an Apollo SL40 comm that are both interfering with the Apollo GX50 GPS. The interference isn't coming from the antennas but the comms themselves. I suspect the local oscillator in the receiver IF stage, but don't know for sure. I seems like there should be a way to shield and/or ground the comms to eliminate the interference. Any assistance is greatly appreciated. Thanks, Lynn M. ________________________________________________________________________________
From: HornetBall(at)aol.com
Date: Feb 23, 2003
Subject: Re: GPS Interference from Comms
Make sure all of the antenna cables are in good shape and properly grounded (best to just replace them). Make sure the power wires and antenna cables are run in separate bundles and that all chasis are properly grounded. Check the KX155 first, it is the noisiest radio and probably also has the oldest wiring. With the wiring and grounds checked out, transmit on the following COM frequencies and watch for GPS drops: 121.15 121.175 121.2 131.25 131.275 131.3 If GPS drops occur, you're looking at adding chokes to the COM transmit antenna and/or moving the GPS antenna. All pretty standard stuff that a good avionics shop should be able to help with. ________________________________________________________________________________
From: "Dave Ford" <dford(at)michweb.net>
Subject: gps interference from comms
Date: Feb 24, 2003
I recently purchase a Garmin GNC300XL that came with a notch filter "T" on the output of the comm antenna to prevent an interference inputing on the gps antenna. If needed contact me offline and I will try to dig up the part no. or an avionics shop can help. Dave Ford RV6 ________________________________________________________________________________
From: MikeEasley(at)aol.com
Date: Feb 25, 2003
Subject: Unswitched Audio Inputs
I am wiring my own panel with a UPSAT SL15M audio panel with 2 unswitched audio inputs.=A0 I have an AOA, EDM900, TruTrak Autopilot, and a Davtron that all need to be connected to an unswitched audio input.=A0 PS Engineering said, "Use a dropping resistor from 100 to 460 ohms on each feed and hook two up to each input".=A0 UPSAT said, "It can't be done, pick two".=A0 TruTrak said, "Just hook all 4 up, it won't hurt a thing".=A0 Anyone else care to cast a vote!!! Thanks, Mike Easley Colorado Springs Lancair ES ________________________________________________________________________________
From: HornetBall(at)aol.com
Date: Feb 25, 2003
Subject: Re: Unswitched Audio Inputs
In a message dated 2/25/03 10:21:08 AM Central Standard Time, MikeEasley(at)aol.com writes: > I am wiring my own panel with a UPSAT SL15M audio panel with 2 unswitched > audio inputs.=A0 I have an AOA, EDM900, TruTrak Autopilot, and a Davtron > that > all need to be connected to an unswitched audio input.=A0 PS Engineering > said, > "Use a dropping resistor from 100 to 460 ohms on each feed and hook two up > to > each input".=A0 UPSAT said, "It can't be done, pick two".=A0 TruTrak said, > "Just > hook all 4 up, it won't hurt a thing".=A0 Anyone else care to cast a > vote!!! > > Thanks, > > Mike Easley > Colorado Springs > Lancair ES > PS Engineering designed the SL-15 and they're right. Actually, both PS Engineering and Tru Trak are right. The PS Engineering solution is more elegant and allows you to tailor the volume of the various audio sources by adjusting resistor values. You'll need this because the power coming from the various sources won't be the same. At headset levels, there's no need for amplifier protection. UPSAT was just doing a CYA (after all, it's their warranty you'll be claiming on if something gets messed up). ________________________________________________________________________________
Date: Feb 28, 2003
From: Tom Brusehaver <cozytom(at)mn.rr.com>
Subject: Used Avionics Blog (sorta)
I have started what I am calling a used avionic BLOG. It isn't a true weblog, but a collection of links to information I have found about getting used avionics. http://home.mn.rr.com/brusehaver/avionics/blog.html It is just a start, I am guessing it'll change quite rapidly until I get to the point of acutally purchasing the radios. Then it may stop, or change slightly. I'd love anyones feedback, additions and suggestions. Thanks ________________________________________________________________________________
Date: Feb 28, 2003
From: John Myers <jmyers(at)powernet.org>
Subject: Narco Mark 12
Anyone know where I might find a pin out listing on an old MK12 (360) radio on the net. I am trying to rig up an old receiver for the hangar but don't have the jumper cable between the radio and the power supply, or what the pin out is for the small cable out of the power supply. Plans are to use it for a receive only unit. If the cable is pin for pin, no problem but was leery about trusting a pin for pin jumper cable, plus was uncertain how the small cable is wired, (assuming was used for speakers and power). Any help appreciated. A search on the net hasn't produced any results yet--still looking. Thanks, John Myers ________________________________________________________________________________
From: "larry OKeefe" <okeefel(at)adelphia.net>
Subject: Nav Antennae
Date: Mar 05, 2003
Building an RV7A with tip tanks. Any suggestions on placement of Nav antennae. should it be in Vertical stabilizer or outer wing area Larry OKeefe RV7A wings ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Avionics-List Digest: 1 Msgs - 03/05/03
Date: Mar 06, 2003
No doubt there are people out there with specific aircraft experience, and the Trial and Error method ultimately is the best guide of what NOT to do. However, a few general rules that you will find in most installation manuals should be adhered to. Keep away by several feet or as far as possible from other radiating antennas. Try to mount the antenna in the "electrical center of mass", i.e. dab smack in the middle of the largest unbroken concentration of metal you can find... usually the belly (but that has it's own problems to consider- you can loose signal on the ground or in high angles of attack; and the antenna is more subject to damage). On composite fuselage aircraft, you will need to build a GROUND PLANE. There are several ways of doing that; Metal Disk, Wire Radials, or Mesh Wire Patch. A old "sparks" amateur radio operator will be more usefull to you than any other group of people I can think of in considering how to best accomplish that and test the results before you start drilling holes in that composite skin. On metal aircraft stay well away from and/or up-wind of NON METALIC surfaces such as windshields, radomes, etc. (they create static). BONDING BONDING BONDING....practice good bonding technique. Clean the mounting surface of paint, alodine the skin...where the antenna will mount & make contact. Be sure the Mounting Studs/Screws, also have a low resistance path. Put Static Discharge wicks on the trailing edge flight control surfaces (may also save your butt if you get hit by lightning the wicks will vaporize instead of a piece of your trailing edge). Put bonding wires between structure and moveable surfaces (static discharge source -- lightning protection) Use Double Shielded Coax, and milstandard (silver coated) coax connectors. Keep the run length to a minimum, (every db of signal loss to the cable is a loss in effective range) and DO NOT run the coax along the same path as the Transponder and DME coaxes. Where these meet, cross at a 90 degree angle to avoid signal coupling. Consider what different antenna TYPES are available for what you want to do, Each has strengths and weaknesses. There certainly are other things you can do to make your radios / antennas work optimally.. By these should give you more than enough to consider. Luc ----- Original Message ----- From: "Avionics-List Digest Server" <avionics-list-digest(at)matronics.com> Subject: Avionics-List Digest: 1 Msgs - 03/05/03 > * > > ================================================== > Online Versions of Today's List Digest Archive > ================================================== > > Today's complete Avionics-List Digest can be also be found in either > of the two Web Links listed below. The .html file includes the Digest > formatted in HTML for viewing with a web browser and features Hyperlinked > Indexes and Message Navigation. The .txt file includes the plain ASCII > version of the Avionics-List Digest and can be viewed with a generic > text editor such as Notepad or with a web browser. > > HTML Version: > > http://www.matronics.com/digest/avionics-list/Digest.Avionics-List.2003-03-0 5.html > > Text Version: > > http://www.matronics.com/digest/avionics-list/Digest.Avionics-List.2003-03-0 5.txt > > > ================================================ > EMail Version of Today's List Digest Archive > ================================================ > > > Avionics-List Digest Archive > --- > Total Messages Posted Wed 03/05/03: 1 > > > Today's Message Index: > ---------------------- > > 1. 09:51 AM - Nav Antennae (larry OKeefe) > > > ________________________________ Message 1 _____________________________________ > > > From: "larry OKeefe" <okeefel(at)adelphia.net> > Subject: Avionics-List: Nav Antennae > > > Building an RV7A with tip tanks. Any suggestions on placement of Nav antennae. > should it be in Vertical stabilizer or outer wing area > Larry OKeefe RV7A wings > > ________________________________________________________________________________
From: "Doug Mattson" <dm10495(at)cedarnet.org>
Subject:
Date: Mar 07, 2003
I have a Bendix encoding altimeter part number 3252013-0101. The altimeter works ok but when I check the output of the encoder it is linear but 500 feet to high. Does anyone know how to adjust this? Doug Mattson dm10495(at)cedarnet.org ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re:
Date: Mar 07, 2003
Yeah.. A 500' ft error is probably Beyond a calibration adjustment, more likely a fried Line Driver Amp. Put it in a box and send it off to an Instrument Shop; in the alternative, install a Blind Encoder (Cheapest option - about $135) if you build an adapter that hooks directly into the Encoding Altimeter harness. (presuming you have the wiring pinout for your encoding altimeter) Don't even try opening the altimeter unless you have a "clean room" (and that doesn't mean a place you vacuumed) and the proper equipment and experience to work on it. Since your asking, I presume you don't. Luc . ----- Original Message ----- From: "Doug Mattson" <dm10495(at)cedarnet.org> Subject: Avionics-List: > > I have a Bendix encoding altimeter part number 3252013-0101. The altimeter > works ok but when I check the output of the encoder it is linear but 500 > feet to high. Does anyone know how to adjust this? > Doug Mattson > dm10495(at)cedarnet.org > > ________________________________________________________________________________
Date: Mar 20, 2003
From: David Andreatta <dandreat(at)earthlink.net>
Subject: Pins for Narco Escort II connector?
Greetings; I'm doing a re-install of an old Narco Escort II, after a major harness cleanup. I could really use a new set of pins for the main card edge connector (v.s. some splicing). At first glance, they appear very similar to the standard Molex pins used in King equipment. BUT, they are smaller and have a slightly different style of contact wiper. They can be easily extracted with the Molex (King) tool. The connector frame is made by Amp, but no part number is visible. I'll try Narco if I get no response from the list. Ideally, someone would have a Tyco/Amp part number so I could order from Digi-Key, Newark, etc. If not, perhaps someone has a small collection in a drawer they might be willing to sell? I'd take about 20, just to have a few spares. Thanks in advance, Dave Andreatta (for off-list reply, mailto:dandreat(at)earthlink.net ) P.S. Just in case someone is looking, Narco has a nice page of manuals and pinouts for their radios. Check out http://www.narcoavionics.com/downloadbody.htm . ________________________________________________________________________________
Date: Mar 22, 2003
From: Matt Dralle <dralle(at)matronics.com>
Subject: 7-Day Matronics List Browse Enhancement...
Dear Listers, Neil Hulin of the Zenith-List at Matronics wrote to me suggesting I add a "total of available messages" column to the 7-Day List Browse Main page, and it seemed like a great idea! I've made the modifications and I think many will find it extremely helpful as well. Have a look at the following URL: http://www.matronics.com/listbrowse/ Best regards, Matt Dralle Matronics Email List Admin... Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft ________________________________________________________________________________
Date: Apr 01, 2003
From: Matt Dralle <dralle(at)matronics.com>
Subject: Matronics ISP Upgrade TODAY...
Dear Listers, The time has finally arrived for the Internet Service Provider (ISP) upgrade! You'll recall that I was looking into upgrading the existing SDSL connection from 768k to 1.1M. As it turned out, the copper line wouldn't support any speeds greater than the current 768k. In light of that news, I just bit-the-bullet and ordered a full, commercial-grade T1 connection. The T1 connection will provide a full-duplex, high priority, 1.5Mb Internet connection which should be a substantial performance enhancement for all of the List services! Pacbell delivered the T1 Loop last week and it tested out fine. This past weekend I pulled the tail circuit from the demark to the office. This afternoon, Tuesday 4/1/03, the ISP is suppose come and install the new router and bring up routing on a test subnet. Assuming that everything checks out okay with the T1, new router, and routing, I will have them swing the main Matronics subnet off the SDSL and onto the T1. In theory, the swing could be nearly transparent to users, but that's usually not the case... ;-) Please expect a bit of instability in connectivity this afternoon as we work though the transition issues. I will post a follow up message when everything is up and running on the new T1 line. Finally, please know that it is solely your Contributions that make these kinds of List upgrades happen! There is no advertising budget (aka, flashing banner ads and annoying pop up browser windows) to pay these bills; operational support is solely from List members like you during the yearly List Fund Raiser. If you would like to make your Contribution to support the Lists and upgrades like this T1 connectivity enhancement, please see the List Contribution Web Site where you can make your Contribution with a Credit Card, PayPal, or Personal Check. You can even get a free List Archive CDROM with a qualifying List Contribution! The URL is: http://www.matronics.com/contribution Thanks again to EVERYONE that made a generous Contribution last year and enabled this awesome upgrade to T1 service! Matt Dralle Matronics Email List Admin. Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft ________________________________________________________________________________
Date: Apr 02, 2003
From: Matt Dralle <dralle(at)matronics.com>
Subject: Matronics ISP Upgrade COMPLETED!
Dear Listers, I just wanted to send out a quick note to let everyone know that the 1.5Mb T1 connection upgrade went smoothly today. They brought up the new line and router yesterday on a test subnet and today the ISP switched over connectivity about 12 noon with little to no incident. I just finished some performance testing, and it appears that actual throughput and interactive response is noticeably improved as advertised! Enjoy! Matt Dralle Matronics Email List Admin. Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft ________________________________________________________________________________
From: "Ralph E. Capen" <recapen(at)earthlink.net>
Subject: #22 size pin removal tool...S-Tec installation
Date: Apr 06, 2003
Hey listers, Anyone out there have a #22 size pin removal/insertion tool? It would be smaller than the tool that you would use on your UPSAT gear (I have one of those). It is for the high density connectors (like S-Tec). If so, where did you get it? I've already tried mouser/digikey/altex...all they have is the bigger ones. I know that this is a fairly inexpensive tool...but when you don't have one it's worth a fortune...! I've already sent a zap to the connector manufacturer - but I thought I'd try you guy/gals too! Thanks for your assistance, Ralph Capen Wiring my 6A in Richardson, TX ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Battery Solenoid (Relay)
Date: Apr 12, 2003
Hi all... Has anyone ever replaced the battery relay on their Beech A23-24 Super III? My relay seems to work fine, but is 36 y/o and uses a Kipvolt Voltage suppressor (diode) to eliminate voltage spikes flushing through the system. I am replacing the battery, ground and starter cables with new cable (AC grade #0 wire for the 40 amp system) and am wondering if anyone has put in a new Aircraft grade battery relay from an aircraft supply (Spruce) source battery relay in place of ours. I can currently remove the battery, diode and battery rely and get current continuity (VOM) through the system from the positive cable to the negative cable or any ground... everything is off... i.e switches, breaker etc. This is what some people think is causing a "hum" in the radios. The "hum" is present with the engine off and running the radios off a fully charged battery. . Additionally, using the AC voltage test setup on the VOM I can detect current flow between the positive cable and ground... any ground. I'm using certer point grounding, but all the avionics manual articles point to RMI induced noise through the hull by poor shielding on the DC power lines. Beech doesn't seem to have these parts anymore. All comments welcomed... David J. Spencer Super3 djs(at)54Transmission.com ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 12, 2003
What resistance do you read between the battery cable and ground. Be sure to take the measurement with the leads swapped as well as standard polarity, i.e. red lead to + and black to -.. If you are NOT using a digital VOM, then also take values in both polarities in more than one RANGE on the VOM (active devices - diodes /transistors - are non-linear.. give you a good clue if the value changes). You may have another noise suppression diode somewhere, and/or an RC type (Band Pass) noise filter , with possibly a bad capacitor in it. Let me know what you get. Luc Martini ----- Original Message ----- From: "David J. Spencer" <djs(at)54Transmission.com> Subject: Avionics-List: Battery Solenoid (Relay) > > Hi all... > > Has anyone ever replaced the battery relay on their Beech A23-24 Super III? > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt Voltage > suppressor (diode) to eliminate voltage spikes flushing through the system. > > I am replacing the battery, ground and starter cables with new cable (AC > grade #0 wire for the 40 amp system) and am wondering if anyone has put in > a > new Aircraft grade battery relay from an aircraft supply (Spruce) source > battery relay in place of ours. > > I can currently remove the battery, diode and battery rely and get current > continuity (VOM) through the system from the positive cable to the > negative cable or any > ground... everything is off... i.e switches, breaker etc. This is what > some > people think is causing a "hum" in the radios. The "hum" is present with > the engine off and running the radios off a fully charged battery. . > Additionally, using the AC voltage test setup on the VOM I can detect > current flow between the positive cable and ground... any ground. > > > I'm using certer point grounding, but all the avionics manual articles > point > to RMI induced noise through the hull by poor shielding on the DC power > lines. > > Beech doesn't seem to have these parts anymore. > > All comments welcomed... > > David J. Spencer > Super3 > djs(at)54Transmission.com > > ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 13, 2003
Luc... There was approximately 11 ohms between the + & - with the correct polarity hook up on the VOM. I took out the battery cable yesterday and found a split in the insulation about 3/8" long which had been taped over. The cable itself had been "crimped" creating a bulge and part of the internal wiring was broken at that point. As best I could tell this open area was not laying on the skin but , rather, pointing away from the skin as the cable lay on the belly of the plane. This is being corrected with new wiring and proper attachments. I hooked the radios up to a DC power source i.e. they are isolated from anything (except the antenna)... and the hum went away. David J. Spencer Super3 djs(at)54Transmission.com ----- Original Message ----- From: "Martini Luc J.R." <martini(at)foxinternet.net> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > What resistance do you read between the battery cable and ground. Be sure > to take the measurement with the leads swapped as well as standard polarity, > i.e. red lead to + and black to -.. If you are NOT using a digital VOM, > then also take values in both polarities in more than one RANGE on the VOM > (active devices - diodes /transistors - are non-linear.. give you a good > clue if the value changes). You may have another noise suppression diode > somewhere, and/or an RC type (Band Pass) noise filter , with possibly a bad > capacitor in it. > > Let me know what you get. > > Luc Martini > ----- Original Message ----- > From: "David J. Spencer" <djs(at)54Transmission.com> > To: > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > Hi all... > > > > Has anyone ever replaced the battery relay on their Beech A23-24 Super > III? > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt Voltage > > suppressor (diode) to eliminate voltage spikes flushing through the > system. > > > > I am replacing the battery, ground and starter cables with new cable (AC > > grade #0 wire for the 40 amp system) and am wondering if anyone has put > in > > a > > new Aircraft grade battery relay from an aircraft supply (Spruce) source > > battery relay in place of ours. > > > > I can currently remove the battery, diode and battery rely and get > current > > continuity (VOM) through the system from the positive cable to the > > negative cable or any > > ground... everything is off... i.e switches, breaker etc. This is what > > some > > people think is causing a "hum" in the radios. The "hum" is present with > > the engine off and running the radios off a fully charged battery. . > > Additionally, using the AC voltage test setup on the VOM I can detect > > current flow between the positive cable and ground... any ground. > > > > > > I'm using certer point grounding, but all the avionics manual articles > > point > > to RMI induced noise through the hull by poor shielding on the DC power > > lines. > > > > Beech doesn't seem to have these parts anymore. > > > > All comments welcomed... > > > > David J. Spencer > > Super3 > > djs(at)54Transmission.com > > > > > > ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 13, 2003
What was the reverse polarity reading? I assume since you did not give a value for another range on the VOM, that it was a Digitial Type. Do you have a 1 amp Current meter? From the ohmic check, that's about the current you are drawing if this is a DC load. If not, hook a 100 ohm resistor in series with the + battery Cable and measure the voltage drop across the resistor. As far as Radio noise in general GOOD GROUNDS (very low ohmic contact) are EVERYTHING. However, there are frequently 2 ground levels, SIGNAL ground and POWER ground. Great care must be taken when assembling your avionics to keep these two seperate, and connect them only at a SINGLE POINT ground. It is not a bad idea to stick your head under the panel, and clean the single point avionics ground to make sure the spade lugs and washers are not oxidized (high ohmic contact) It does not surprise me that with EXTERNAL DC power, that you do NOT have radio hum. since your do NOT have a source of noise.. generator/alternator, motors, etc. You did not mention if it was the + or the - battery lead that had a crimp splice in it. If it was in the + lead. other than creating a voltage drop... which would be reflected to the voltage regulator, i.e. the generator/alternator would be putting out more voltage than it should because it senses a Battery slightly low voltage condition. If on the other hand it was on the - side. as far as the radios go, it would be like putting a resistance between the - battery terminal and Chasis Ground. This could conceiveably cause the noise floor to be raised...but not likely if yourGenrator/Alternator grouind is good... By the way... have to checked that to make sure you have a good & clean grounding strap from the engine to the firewall ?? Luc ssage ----- From: "David J. Spencer" <djs(at)54Transmission.com> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Luc... > > There was approximately 11 ohms between the + & - with the correct polarity > hook up on the VOM. > > I took out the battery cable yesterday and found a split in the insulation > about 3/8" long which had been taped over. The cable itself had been > "crimped" creating a bulge and part of the internal wiring was broken at > that point. > > As best I could tell this open area was not laying on the skin but , rather, > pointing away from the skin as the cable lay on the belly of the plane. > > This is being corrected with new wiring and proper attachments. > > I hooked the radios up to a DC power source i.e. they are isolated from > anything (except the antenna)... and the hum went away. > > David J. Spencer > Super3 > djs(at)54Transmission.com > > ----- Original Message ----- > From: "Martini Luc J.R." <martini(at)foxinternet.net> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > What resistance do you read between the battery cable and ground. Be sure > > to take the measurement with the leads swapped as well as standard > polarity, > > i.e. red lead to + and black to -.. If you are NOT using a digital VOM, > > then also take values in both polarities in more than one RANGE on the VOM > > (active devices - diodes /transistors - are non-linear.. give you a good > > clue if the value changes). You may have another noise suppression diode > > somewhere, and/or an RC type (Band Pass) noise filter , with possibly a > bad > > capacitor in it. > > > > Let me know what you get. > > > > Luc Martini > > ----- Original Message ----- > > From: "David J. Spencer" <djs(at)54Transmission.com> > > To: > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > Hi all... > > > > > > Has anyone ever replaced the battery relay on their Beech A23-24 Super > > III? > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt Voltage > > > suppressor (diode) to eliminate voltage spikes flushing through the > > system. > > > > > > I am replacing the battery, ground and starter cables with new cable > (AC > > > grade #0 wire for the 40 amp system) and am wondering if anyone has put > > in > > > a > > > new Aircraft grade battery relay from an aircraft supply (Spruce) > source > > > battery relay in place of ours. > > > > > > I can currently remove the battery, diode and battery rely and get > > current > > > continuity (VOM) through the system from the positive cable to the > > > negative cable or any > > > ground... everything is off... i.e switches, breaker etc. This is what > > > some > > > people think is causing a "hum" in the radios. The "hum" is present > with > > > the engine off and running the radios off a fully charged battery. . > > > Additionally, using the AC voltage test setup on the VOM I can detect > > > current flow between the positive cable and ground... any ground. > > > > > > > > > I'm using certer point grounding, but all the avionics manual articles > > > point > > > to RMI induced noise through the hull by poor shielding on the DC power > > > lines. > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > All comments welcomed... > > > > > > David J. Spencer > > > Super3 > > > djs(at)54Transmission.com > > > > > > > > > > > > ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 14, 2003
Luc... The resistance didn't change with a reverse in polarity... it rarely does. My VOM has a 1 amp capability. When I set it to AC voltage and ran a check with the +/- cables I got .245 volt flow in either direction. You raise an interesting point about the two different types of grounds... power and audio. Both are separated in the wiring harness, but connected to the same center point ground. Should there be two center point grounds? Everything is very clean as I just rebuilt the wiring harness. I have had it out twice and rechecked for faulty wiring or shielding touching the center wire and it checks out just fine. With the DC power source hooked directly to the power cable (I come off the power bus with one power cable to the audio panel, 2 NavComs, transponder, ADF and intercom though another set of breakers) to the radio stack, the only thing I eliminated was the battery and the associated wiring... all other noise sources (motors, alternator, gyros, etc.) were always off. I was getting the hum just off the battery power with no other motors, solenoids, regulators, gyros or anything turned on even connected. The + cable was the one with the crimp in it. The negative cable is only about 18" long and connected to the frame. I have not checked the grounding strap from the engine to the firewall within the last two months, but will be checking that also along with the starter cables, ammeter cables (which I found had some "burned spots" on them which was hidden from view until you "unbundled" all the wiring) and installing an AmeriKing DC filter and Alternator filter. I've always though Last year I replaced all the antenna cables as I found them to be bundled and taped to the + power cable. I also replaced all the comm antennae (fiberglass and cracked) with stainless steel, which helped a lot. The controlled field I fly out of has a "cone of static" which many complain about, but the FAA and FCC can't seem to isolate or do anything about, but rather claim it's everybody's radios... when you lift off, sometimes, the static is so bad you have to turn off the radios... I also replaced the alternator, voltage regulator and OV regulator plus all the associated wiring as some Avionics moron had butt spliced the field wire "INSIDE" the firewall cannon plug. The butt splice was broken and, of course, the field wire was going to ground. After 3 avionics shops checked my alternator I took it out myself and found 3 diodes were bad... AeroElectric found that one more was bad when they replaced my alternator with an upgraded version with larger bearings. Yesterday as I pulled out the + battery power cable, I found all the lights, strobe, electric fuel pump, and fuel sensors taped (relatively new looking tape) to the + power cable. Needless to say, during it's 36 year existence, maintenance has always been done in FAA certified shops and done with a very high level of poor quality. I honestly think this is a wiring problem relative to 36 y/o wire, but I won't know until I get all the wiring replaced and according to Beech wiring diagram specifications. Thanks for you help and input... David J. Spencer Super3 djs(at)54Transmission.com ----- Original Message ----- From: "Martini Luc J.R." <martini(at)foxinternet.net> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > What was the reverse polarity reading? I assume since you did not give a > value for another range on the VOM, that it was a Digitial Type. > > Do you have a 1 amp Current meter? From the ohmic check, that's about the > current you are drawing if this is a DC load. If not, hook a 100 ohm > resistor in series with the + battery Cable and measure the voltage drop > across the resistor. > > As far as Radio noise in general GOOD GROUNDS (very low ohmic contact) are > EVERYTHING. > > However, there are frequently 2 ground levels, SIGNAL ground and POWER > ground. Great care must be taken when assembling your avionics to keep > these two seperate, and connect them only at a SINGLE POINT ground. > > It is not a bad idea to stick your head under the panel, and clean the > single point avionics ground to make sure the spade lugs and washers are > not oxidized (high ohmic contact) > > It does not surprise me that with EXTERNAL DC power, that you do NOT have > radio hum. since your do NOT have a source of noise.. generator/alternator, > motors, etc. > > You did not mention if it was the + or the - battery lead that had a crimp > splice in it. If it was in the + lead. other than creating a voltage > drop... which would be reflected to the voltage regulator, i.e. the > generator/alternator would be putting out more voltage than it should > because it senses a Battery slightly low voltage condition. If on the > other hand it was on the - side. as far as the radios go, it would be like > putting a resistance between the - battery terminal and Chasis Ground. This > could conceiveably cause the noise floor to be raised...but not likely if > yourGenrator/Alternator grouind is good... By the way... have to checked > that to make sure you have a good & clean grounding strap from the engine to > the firewall ?? > > Luc > > > ssage ----- > From: "David J. Spencer" <djs(at)54Transmission.com> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Luc... > > > > There was approximately 11 ohms between the + & - with the correct > polarity > > hook up on the VOM. > > > > I took out the battery cable yesterday and found a split in the insulation > > about 3/8" long which had been taped over. The cable itself had been > > "crimped" creating a bulge and part of the internal wiring was broken at > > that point. > > > > As best I could tell this open area was not laying on the skin but , > rather, > > pointing away from the skin as the cable lay on the belly of the plane. > > > > This is being corrected with new wiring and proper attachments. > > > > I hooked the radios up to a DC power source i.e. they are isolated from > > anything (except the antenna)... and the hum went away. > > > > David J. Spencer > > Super3 > > djs(at)54Transmission.com > > > > ----- Original Message ----- > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > What resistance do you read between the battery cable and ground. Be > sure > > > to take the measurement with the leads swapped as well as standard > > polarity, > > > i.e. red lead to + and black to -.. If you are NOT using a digital VOM, > > > then also take values in both polarities in more than one RANGE on the > VOM > > > (active devices - diodes /transistors - are non-linear.. give you a good > > > clue if the value changes). You may have another noise suppression diode > > > somewhere, and/or an RC type (Band Pass) noise filter , with possibly a > > bad > > > capacitor in it. > > > > > > Let me know what you get. > > > > > > Luc Martini > > > ----- Original Message ----- > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > To: > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > Has anyone ever replaced the battery relay on their Beech A23-24 Super > > > III? > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt Voltage > > > > suppressor (diode) to eliminate voltage spikes flushing through the > > > system. > > > > > > > > I am replacing the battery, ground and starter cables with new cable > > (AC > > > > grade #0 wire for the 40 amp system) and am wondering if anyone has > put > > > in > > > > a > > > > new Aircraft grade battery relay from an aircraft supply (Spruce) > > source > > > > battery relay in place of ours. > > > > > > > > I can currently remove the battery, diode and battery rely and get > > > current > > > > continuity (VOM) through the system from the positive cable to the > > > > negative cable or any > > > > ground... everything is off... i.e switches, breaker etc. This is > what > > > > some > > > > people think is causing a "hum" in the radios. The "hum" is present > > with > > > > the engine off and running the radios off a fully charged battery. . > > > > Additionally, using the AC voltage test setup on the VOM I can detect > > > > current flow between the positive cable and ground... any ground. > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > articles > > > > point > > > > to RMI induced noise through the hull by poor shielding on the DC > power > > > > lines. > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > All comments welcomed... > > > > > > > > David J. Spencer > > > > Super3 > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 14, 2003
Luc... Another point. I always thought it strange that on start-up with a well charged battery the ammeter always showed a charge for about 30-45 seconds when I turn on the alternator. At times, with everything, but the intercom off it would simply cycle charge like I was turning something on/off at regular cycles. This, as you point out, was probably due to the + cable being broken indicating a low battery condition to the VR. I checked the alternator wiring yesterday and it is just fine... no grounded field wire and everything else is normal. David ----- Original Message ----- From: "Martini Luc J.R." <martini(at)foxinternet.net> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > What was the reverse polarity reading? I assume since you did not give a > value for another range on the VOM, that it was a Digitial Type. > > Do you have a 1 amp Current meter? From the ohmic check, that's about the > current you are drawing if this is a DC load. If not, hook a 100 ohm > resistor in series with the + battery Cable and measure the voltage drop > across the resistor. > > As far as Radio noise in general GOOD GROUNDS (very low ohmic contact) are > EVERYTHING. > > However, there are frequently 2 ground levels, SIGNAL ground and POWER > ground. Great care must be taken when assembling your avionics to keep > these two seperate, and connect them only at a SINGLE POINT ground. > > It is not a bad idea to stick your head under the panel, and clean the > single point avionics ground to make sure the spade lugs and washers are > not oxidized (high ohmic contact) > > It does not surprise me that with EXTERNAL DC power, that you do NOT have > radio hum. since your do NOT have a source of noise.. generator/alternator, > motors, etc. > > You did not mention if it was the + or the - battery lead that had a crimp > splice in it. If it was in the + lead. other than creating a voltage > drop... which would be reflected to the voltage regulator, i.e. the > generator/alternator would be putting out more voltage than it should > because it senses a Battery slightly low voltage condition. If on the > other hand it was on the - side. as far as the radios go, it would be like > putting a resistance between the - battery terminal and Chasis Ground. This > could conceiveably cause the noise floor to be raised...but not likely if > yourGenrator/Alternator grouind is good... By the way... have to checked > that to make sure you have a good & clean grounding strap from the engine to > the firewall ?? > > Luc > > > ssage ----- > From: "David J. Spencer" <djs(at)54Transmission.com> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Luc... > > > > There was approximately 11 ohms between the + & - with the correct > polarity > > hook up on the VOM. > > > > I took out the battery cable yesterday and found a split in the insulation > > about 3/8" long which had been taped over. The cable itself had been > > "crimped" creating a bulge and part of the internal wiring was broken at > > that point. > > > > As best I could tell this open area was not laying on the skin but , > rather, > > pointing away from the skin as the cable lay on the belly of the plane. > > > > This is being corrected with new wiring and proper attachments. > > > > I hooked the radios up to a DC power source i.e. they are isolated from > > anything (except the antenna)... and the hum went away. > > > > David J. Spencer > > Super3 > > djs(at)54Transmission.com > > > > ----- Original Message ----- > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > What resistance do you read between the battery cable and ground. Be > sure > > > to take the measurement with the leads swapped as well as standard > > polarity, > > > i.e. red lead to + and black to -.. If you are NOT using a digital VOM, > > > then also take values in both polarities in more than one RANGE on the > VOM > > > (active devices - diodes /transistors - are non-linear.. give you a good > > > clue if the value changes). You may have another noise suppression diode > > > somewhere, and/or an RC type (Band Pass) noise filter , with possibly a > > bad > > > capacitor in it. > > > > > > Let me know what you get. > > > > > > Luc Martini > > > ----- Original Message ----- > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > To: > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > Has anyone ever replaced the battery relay on their Beech A23-24 Super > > > III? > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt Voltage > > > > suppressor (diode) to eliminate voltage spikes flushing through the > > > system. > > > > > > > > I am replacing the battery, ground and starter cables with new cable > > (AC > > > > grade #0 wire for the 40 amp system) and am wondering if anyone has > put > > > in > > > > a > > > > new Aircraft grade battery relay from an aircraft supply (Spruce) > > source > > > > battery relay in place of ours. > > > > > > > > I can currently remove the battery, diode and battery rely and get > > > current > > > > continuity (VOM) through the system from the positive cable to the > > > > negative cable or any > > > > ground... everything is off... i.e switches, breaker etc. This is > what > > > > some > > > > people think is causing a "hum" in the radios. The "hum" is present > > with > > > > the engine off and running the radios off a fully charged battery. . > > > > Additionally, using the AC voltage test setup on the VOM I can detect > > > > current flow between the positive cable and ground... any ground. > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > articles > > > > point > > > > to RMI induced noise through the hull by poor shielding on the DC > power > > > > lines. > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > All comments welcomed... > > > > > > > > David J. Spencer > > > > Super3 > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 14, 2003
Hello again There can be a very considerable difference in resitance readings of a VOM for forward v. reverse polarity if you have an "Active Device" in the circuit... i.e. a Diode, or a Transistor. Looking from the battery, you could be looking at several of these, (diodes or transistors) which are used for noise suppression, voltage spike protection, even internally in a voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated by a circuit breaker. If there is No change as you indicated, that simply verifies that you likely DO NOT have an Active Device in the Battery Bus Circuit, since Active Devices are very NON LINEAR, i.e., the reading you get on a VOM is typically MUCH higher in one polarity than the other. If your VOM has a 1 amp direct reading capability, the way to proceed is to disconnected the + lead from the battery. Set your VOM to DC CURRENT (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in SERIES with the battery, i.e., VOM - lead to battery cable (where the LOAD is), and + lead to the battery + lead (Current Source). The reading you will get will be in either MILLIAMPS (ma) or AMPS (A).. depending on your meter...if the scale is calibrated in (ma), move the decimal place to the right 3 spaces (X 1000) for (amps) If you are using your fully charged aircraft battery,. you should get 1.09 Amps showing on the meter.: 12 VDC/11 OHMS = 1.09 AMPS. Note that if you use external power the voltage might be higher, up to 14 volts.. that might damage your VOM since that is 1.3 Amps. You may have done this already according to your note, but you read the VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter is different, I have no way of knowing what the .245 you referred to really is. The nice thing about using a CURRENT METER is that you can leave it hooked up and go disconnect various things that power goes to, i.e voltage regulators, bulkhead connectors, circuit breakers, etc. and with a quick check see if the current dropped to ZERO.... BINGO... your problem is in THAT CIRCUIT. As to your question about Avionics Signal and Power Grounds. NO, they MUST be connected together at ONE and ONLY one place for noise immunity... also helps with lighning protection. Signal ground is not the same as AUDIO ground. That is not to say that Avionics Shops do things right... as you have found out. There is one other thing I should tell you about. Audio Panels are an even MORE complicated item. In Audio Panels, they may have as many as 2 MORE types of Grounds. King (KMA-24) is famous for this. You have to Isolate the AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot audio from ANY OTHER audio ground, as well as isolation from CHASIS GROUND. These suckers can be real bears, and the source of Noise PICKUP (from external sources such as motors, sparks (like bad shielding on spark plug wires) and even external to the aircraft.. industrial sources. The Noise Zone you mention is intriguing. There are two ways of looking at the problem.. 1) that there exists a NOISE SOURCE in that area, or 2), that there exists a SHIELD from radiation. I believe the first is what everybody has been focused on. However, the second is just as likely if not more so. For example, if there is a significant magnetic disturbance in the area, or a very large metalic structure in the area, or a hill with a lot of iron content.. etc. etc. these can shield the background RF Noise Level The Automatic Gain Control (AGC) circuits in you radios, and/or audio panel, would compensate by INCREASING the GAIN... that would result in audio STATIC...exactly like what you get when listening to your AM radio in the car when you drive through a tunnel. I got the point you made that you had EVERYTHING disconnected except the Battery and the Avionics DC bus and of course the radios that power them.. One thing you should also do, is turn of your Transponder. Also, if the Antenna Coax for the Transponder and the DME (if you have one) are run parallel with other wiring bundles, that can be a source of severe static. I always use Double Shielded Coax for these devices... some Av Shops do not... and if I have to cross a wire bundle, I do it at as close to 90 degrees as I can.(the Electric and Magnetic Fields no not couple to the other cable when; you do that) Obviously it pays to keep these Coax leads as short as possible (but must generally be no shorter than 3 feet (1/2 wave length). Another general practice to follow is good GROUND PLANES for the antennas. What that means generally, is as much flat metal around the antenna as your airplane and avionics can afford; keep radiating elements like DME and Transponder seperated by 6' from each other.. as well as from very low signal sources like LORAN, GPS...Keep the Comm antenna away from those as well... and strangely enough, keep these well away and UP-STREAM (airstream) from non-electrically conductive surfaces such as Plexiglass, Fiberglass etc. (these create static electricity that can couple the discharge via inonizatiotion of the airstream) Then, have a Good Low ohmic contact for the antennas. That means cleaning away all paint where the antenna mounts, and Alodining the area. and on the INSIDE of the airplane, make sure that your have a good clean contact in like fashion for the antenna mounting nuts/bolts. I just received another e-mail from you... about the odd charging habits of your airplane. Keep in mind, that a fully charged battery is 12 VDC. However, your voltage regulator puts out between 13.5 and 14.00 volts depending on the current draw, and the internal setting of you voltage regulator. You would be surprised at the variation in "Idling Current" from one Regulator to the next. So, it does NOT surprise me that even after starting your engines with a full battery, that they do a little chargin for a while. What DOES surprise me is the CYCLING you mentioned. That was common in the old days of RELAY type voltage regulagtors, but NOT for Solid state Alternator Regulators. Do you have some sort of switching arangement for left/right engine alternators? Luc ----- Original Message ----- From: "David J. Spencer" <djs(at)54Transmission.com> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Luc... > > The resistance didn't change with a reverse in polarity... it rarely does. > > My VOM has a 1 amp capability. When I set it to AC voltage and ran a check > with the +/- cables I got .245 volt flow in either direction. > > You raise an interesting point about the two different types of grounds... > power and audio. Both are separated in the wiring harness, but connected to > the same center point ground. Should there be two center point grounds? > > Everything is very clean as I just rebuilt the wiring harness. I have had > it out twice and rechecked for faulty wiring or shielding touching the > center wire and it checks out just fine. > > With the DC power source hooked directly to the power cable (I come off the > power bus with one power cable to the audio panel, 2 NavComs, transponder, > ADF and intercom though another set of breakers) to the radio stack, the > only thing I eliminated was the battery and the associated wiring... all > other noise sources (motors, alternator, gyros, etc.) were always off. I > was getting the hum just off the battery power with no other motors, > solenoids, regulators, gyros or anything turned on even connected. > > The + cable was the one with the crimp in it. The negative cable is only > about 18" long and connected to the frame. > > I have not checked the grounding strap from the engine to the firewall > within the last two months, but will be checking that also along with the > starter cables, ammeter cables (which I found had some "burned spots" on > them which was hidden from view until you "unbundled" all the wiring) and > installing an AmeriKing DC filter and Alternator filter. I've always though > > Last year I replaced all the antenna cables as I found them to be bundled > and taped to the + power cable. I also replaced all the comm antennae > (fiberglass and cracked) with stainless steel, which helped a lot. The > controlled field I fly out of has a "cone of static" which many complain > about, but the FAA and FCC can't seem to isolate or do anything about, but > rather claim it's everybody's radios... when you lift off, sometimes, the > static is so bad you have to turn off the radios... > > I also replaced the alternator, voltage regulator and OV regulator plus all > the associated wiring as some Avionics moron had butt spliced the field wire > "INSIDE" the firewall cannon plug. The butt splice was broken and, of > course, the field wire was going to ground. After 3 avionics shops checked > my alternator I took it out myself and found 3 diodes were bad... > AeroElectric found that one more was bad when they replaced my alternator > with an upgraded version with larger bearings. > > Yesterday as I pulled out the + battery power cable, I found all the lights, > strobe, electric fuel pump, and fuel sensors taped (relatively new looking > tape) to the + power cable. Needless to say, during it's 36 year existence, > maintenance has always been done in FAA certified shops and done with a very > high level of poor quality. > > I honestly think this is a wiring problem relative to 36 y/o wire, but I > won't know until I get all the wiring replaced and according to Beech wiring > diagram specifications. > > Thanks for you help and input... > > David J. Spencer > Super3 > djs(at)54Transmission.com > > > ----- Original Message ----- > From: "Martini Luc J.R." <martini(at)foxinternet.net> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > What was the reverse polarity reading? I assume since you did not give a > > value for another range on the VOM, that it was a Digitial Type. > > > > Do you have a 1 amp Current meter? From the ohmic check, that's about the > > current you are drawing if this is a DC load. If not, hook a 100 ohm > > resistor in series with the + battery Cable and measure the voltage drop > > across the resistor. > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic contact) are > > EVERYTHING. > > > > However, there are frequently 2 ground levels, SIGNAL ground and POWER > > ground. Great care must be taken when assembling your avionics to keep > > these two seperate, and connect them only at a SINGLE POINT ground. > > > > It is not a bad idea to stick your head under the panel, and clean the > > single point avionics ground to make sure the spade lugs and washers are > > not oxidized (high ohmic contact) > > > > It does not surprise me that with EXTERNAL DC power, that you do NOT have > > radio hum. since your do NOT have a source of noise.. > generator/alternator, > > motors, etc. > > > > You did not mention if it was the + or the - battery lead that had a crimp > > splice in it. If it was in the + lead. other than creating a voltage > > drop... which would be reflected to the voltage regulator, i.e. the > > generator/alternator would be putting out more voltage than it should > > because it senses a Battery slightly low voltage condition. If on the > > other hand it was on the - side. as far as the radios go, it would be > like > > putting a resistance between the - battery terminal and Chasis Ground. > This > > could conceiveably cause the noise floor to be raised...but not likely if > > yourGenrator/Alternator grouind is good... By the way... have to checked > > that to make sure you have a good & clean grounding strap from the engine > to > > the firewall ?? > > > > Luc > > > > > > ssage ----- > > From: "David J. Spencer" <djs(at)54Transmission.com> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > Luc... > > > > > > There was approximately 11 ohms between the + & - with the correct > > polarity > > > hook up on the VOM. > > > > > > I took out the battery cable yesterday and found a split in the > insulation > > > about 3/8" long which had been taped over. The cable itself had been > > > "crimped" creating a bulge and part of the internal wiring was broken at > > > that point. > > > > > > As best I could tell this open area was not laying on the skin but , > > rather, > > > pointing away from the skin as the cable lay on the belly of the plane. > > > > > > This is being corrected with new wiring and proper attachments. > > > > > > I hooked the radios up to a DC power source i.e. they are isolated from > > > anything (except the antenna)... and the hum went away. > > > > > > David J. Spencer > > > Super3 > > > djs(at)54Transmission.com > > > > > > ----- Original Message ----- > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > To: > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > What resistance do you read between the battery cable and ground. Be > > sure > > > > to take the measurement with the leads swapped as well as standard > > > polarity, > > > > i.e. red lead to + and black to -.. If you are NOT using a digital > VOM, > > > > then also take values in both polarities in more than one RANGE on the > > VOM > > > > (active devices - diodes /transistors - are non-linear.. give you a > good > > > > clue if the value changes). You may have another noise suppression > diode > > > > somewhere, and/or an RC type (Band Pass) noise filter , with possibly > a > > > bad > > > > capacitor in it. > > > > > > > > Let me know what you get. > > > > > > > > Luc Martini > > > > ----- Original Message ----- > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > To: > > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > > > Has anyone ever replaced the battery relay on their Beech A23-24 > Super > > > > III? > > > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt > Voltage > > > > > suppressor (diode) to eliminate voltage spikes flushing through the > > > > system. > > > > > > > > > > I am replacing the battery, ground and starter cables with new > cable > > > (AC > > > > > grade #0 wire for the 40 amp system) and am wondering if anyone has > > put > > > > in > > > > > a > > > > > new Aircraft grade battery relay from an aircraft supply (Spruce) > > > source > > > > > battery relay in place of ours. > > > > > > > > > > I can currently remove the battery, diode and battery rely and get > > > > current > > > > > continuity (VOM) through the system from the positive cable to the > > > > > negative cable or any > > > > > ground... everything is off... i.e switches, breaker etc. This is > > what > > > > > some > > > > > people think is causing a "hum" in the radios. The "hum" is > present > > > with > > > > > the engine off and running the radios off a fully charged battery. > . > > > > > Additionally, using the AC voltage test setup on the VOM I can > detect > > > > > current flow between the positive cable and ground... any ground. > > > > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > > articles > > > > > point > > > > > to RMI induced noise through the hull by poor shielding on the DC > > power > > > > > lines. > > > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > > > All comments welcomed... > > > > > > > > > > David J. Spencer > > > > > Super3 > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 14, 2003
Wow... what a wealth of information... You will never know how much this is helping and I really appreciate your input. First of all this is a single engine plane (1967 Beech Musketeer, 200 hp Lycoming with fuel injection, A23-24 or Super III), so I only have one alternator. Now to the cycling which I mentioned. The VR was a contact type which I replaced with a Zeftronic unit. The cycling continued. I then replaced the OV regulator with the matched Zeftronic solid state affair and the cycling has stopped. I thought it might be one or the other as nothing except the alternator and intercom were running when I last got fed up with the noise. Turn off the alternator and the noise went away. It just made sense and the VR & OV were both original equipment and 36+ years old. Thank you... You are correct for correcting me about resistance with or without inline devices... I just wasn't thinking when I said there is no difference as I always try to simplify the circuit to it's barest essentials and then load on devices until I find a problem. Just my untrained methodology. I will run the amperage test when I get some new battery cable installed. I bought #4 as it met the continuous usage requirements as per the chart on page 1-10 of Robert G. Horan's "Avionics Installation Handbook"... HOWEVER, the plane came with #0 wire and I am going to replace it with #0 wire. The run from the battery to the starter solenoid is about 12 feet (12 volt system) and then another 5 feet to the starter. The alternator is a 40 amp unit, but my guess is that the amperage on engine start may be high enough to warrant the heavier cable. Anyway what the hell it's just money and it "might" prevent something I don't understand is going on... safe is better than crispy. Now to the audio panel. I have a Terra TMA 230 with a marker beacon and two Terra TXN-960 NavComs with glide slopes and ILS which I call a radio stack. I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has three audio grounds (connected) and one chassis ground. AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR THE ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I also have not put a ground on the radio trays themselves... I think I should. Also, my centerpoint system is a terminal block where all the posts are connected to the same frame point as the ground. This allowed me to create a neat little area where all the grounds (except the ones I just mentioned) are located. The intercom requires insulating all the headset jacks (with isolation washers) and using the centerpoint ground. Now to the Cone of Static... below is a diagram of the airport in relationship to some 1600' AGL radio, TV & Microwave transmission towers which are South of the field about 5 miles. The airport is directly between the towers and Downtown Dallas Texas. Is it possible that the towers could be transmitting a directional signal toward downtown? ++++ +++++ Radio Transmission towers (~15 @ 1600' AGL) +++++ about five miles to towers | | | Runway (17/35) | | about three miles DOWNTOWN DALLAS TEXAS As for large metallic structures...there are two hangars built by Howard Hughes for something really big right on the 17/35 runway. Other than that there is an FBI/U.S. Customs helicopter hangar (which tends to be rather a secretive place) on the South end of the field and a medium sized strip mall just across a highway to the South. There is also a six story Wells Fargo Bank down by the FBI. There is a National Guard Armory on the West side of the field which, I believe has some radio antennae sticking up in the wooded area adjacent to it... I'll check on the way home. My wife (she's a pilot also) says she thinks the bank tower has dish antennae on it... either the bank or the FBI. That's her side of the plane so I never look out there, because I don't want to see what she's going to hit, and will check on it on way home. The antennas are well grounded, but are on the aft slope of the top of the fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF which required triaxial cable I changed EVERYTHING to triaxial as it just seemed the logical thing to do. They are too close together (about 2 feet apart), but are about 5 feet aft of the Loran antenna. The transponder is under the foward fuselage (blade type) and the ADF & marker beacon are on the bottom aft fuselage. The aftmost comm antenna is very close to the vertical stabilizer which has an ABS plastic shroud on the leading edge to affect airflow. I never thought much about the static from plastic as all I've read indicates that our plane is too slow... we cruise at ~145-150 mph with take-off and climb at 90-100 mph. Should I install some static wicks? We only get this static garbage at this airport... no where else we have flown has given us any problems and we have been into some strange places like the Arizona & New Mexico desert and along the U.S./ Mexico border. You will never know how much you are helping... I tend to be a rather tenacious person and want very much to understand as much as possible about what is going on and how to eliminate it... if possible. David ----- Original Message ----- From: "Martini Luc J.R." <martini(at)foxinternet.net> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Hello again > > There can be a very considerable difference in resitance readings of a VOM > for forward v. reverse polarity if you have an "Active Device" in the > circuit... i.e. a Diode, or a Transistor. Looking from the battery, you > could be looking at several of these, (diodes or transistors) which are > used for noise suppression, voltage spike protection, even internally in a > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated by a > circuit breaker. > > If there is No change as you indicated, that simply verifies that you likely > DO NOT have an Active Device in the Battery Bus Circuit, since Active > Devices are very NON LINEAR, i.e., the reading you get on a VOM is typically > MUCH higher in one polarity than the other. > > If your VOM has a 1 amp direct reading capability, the way to proceed is to > disconnected the + lead from the battery. Set your VOM to DC CURRENT > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in SERIES > with the battery, i.e., VOM - lead to battery cable (where the LOAD is), and > + lead to the battery + lead (Current Source). > > The reading you will get will be in either MILLIAMPS (ma) or AMPS (A).. > depending on your meter...if the scale is calibrated in (ma), move the > decimal place to the right 3 spaces (X 1000) for (amps) > > If you are using your fully charged aircraft battery,. you should get 1.09 > Amps showing on the meter.: > > 12 VDC/11 OHMS = 1.09 AMPS. > > Note that if you use external power the voltage might be higher, up to 14 > volts.. that might damage your VOM since that is 1.3 Amps. > > You may have done this already according to your note, but you read the > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter is > different, I have no way of knowing what the .245 you referred to really is. > > The nice thing about using a CURRENT METER is that you can leave it hooked > up and go disconnect various things that power goes to, i.e voltage > regulators, bulkhead connectors, circuit breakers, etc. and with a quick > check see if the current dropped to ZERO.... BINGO... your problem is in > THAT CIRCUIT. > > As to your question about Avionics Signal and Power Grounds. NO, they MUST > be connected together at ONE and ONLY one place for noise immunity... also > helps with lighning protection. Signal ground is not the same as AUDIO > ground. > > That is not to say that Avionics Shops do things right... as you have found > out. > > There is one other thing I should tell you about. Audio Panels are an even > MORE complicated item. In Audio Panels, they may have as many as 2 MORE > types of Grounds. King (KMA-24) is famous for this. You have to Isolate the > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot audio > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND. > These suckers can be real bears, and the source of Noise PICKUP (from > external sources such as motors, sparks (like bad shielding on spark plug > wires) and even external to the aircraft.. industrial sources. > > The Noise Zone you mention is intriguing. There are two ways of looking at > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2), that > there exists a SHIELD from radiation. > > I believe the first is what everybody has been focused on. However, the > second is just as likely if not more so. For example, if there is a > significant magnetic disturbance in the area, or a very large metalic > structure in the area, or a hill with a lot of iron content.. etc. etc. > these can shield the background RF Noise Level The Automatic Gain Control > (AGC) circuits in you radios, and/or audio panel, would compensate by > INCREASING the GAIN... that would result in audio STATIC...exactly like what > you get when listening to your AM radio in the car when you drive through a > tunnel. > > I got the point you made that you had EVERYTHING disconnected except the > Battery and the Avionics DC bus and of course the radios that power them.. > One thing you should also do, is turn of your Transponder. Also, if the > Antenna Coax for the Transponder and the DME (if you have one) are run > parallel with other wiring bundles, that can be a source of severe static. > I always use Double Shielded Coax for these devices... some Av Shops do > not... and if I have to cross a wire bundle, I do it at as close to 90 > degrees as I can.(the Electric and Magnetic Fields no not couple to the > other cable when; you do that) Obviously it pays to keep these Coax leads > as short as possible (but must generally be no shorter than 3 feet (1/2 wave > length). > > Another general practice to follow is good GROUND PLANES for the antennas. > What that means generally, is as much flat metal around the antenna as your > airplane and avionics can afford; keep radiating elements like DME and > Transponder seperated by 6' from each other.. as well as from very low > signal sources like LORAN, GPS...Keep the Comm antenna away from those as > well... and strangely enough, keep these well away and UP-STREAM > (airstream) from non-electrically conductive surfaces such as Plexiglass, > Fiberglass etc. (these create static electricity that can couple the > discharge via inonizatiotion of the airstream) Then, have a Good Low ohmic > contact for the antennas. That means cleaning away all paint where the > antenna mounts, and Alodining the area. and on the INSIDE of the airplane, > make sure that your have a good clean contact in like fashion for the > antenna mounting nuts/bolts. > > I just received another e-mail from you... about the odd charging habits of > your airplane. Keep in mind, that a fully charged battery is 12 VDC. > However, your voltage regulator puts out between 13.5 and 14.00 volts > depending on the current draw, and the internal setting of you voltage > regulator. You would be surprised at the variation in "Idling Current" from > one Regulator to the next. So, it does NOT surprise me that even after > starting your engines with a full battery, that they do a little chargin for > a while. What DOES surprise me is the CYCLING you mentioned. That was > common in the old days of RELAY type voltage regulagtors, but NOT for Solid > state Alternator Regulators. > > Do you have some sort of switching arangement for left/right engine > alternators? > > Luc > > > ----- Original Message ----- > From: "David J. Spencer" <djs(at)54Transmission.com> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Luc... > > > > The resistance didn't change with a reverse in polarity... it rarely does. > > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran a > check > > with the +/- cables I got .245 volt flow in either direction. > > > > You raise an interesting point about the two different types of grounds... > > power and audio. Both are separated in the wiring harness, but connected > to > > the same center point ground. Should there be two center point grounds? > > > > Everything is very clean as I just rebuilt the wiring harness. I have had > > it out twice and rechecked for faulty wiring or shielding touching the > > center wire and it checks out just fine. > > > > With the DC power source hooked directly to the power cable (I come off > the > > power bus with one power cable to the audio panel, 2 NavComs, transponder, > > ADF and intercom though another set of breakers) to the radio stack, the > > only thing I eliminated was the battery and the associated wiring... all > > other noise sources (motors, alternator, gyros, etc.) were always off. I > > was getting the hum just off the battery power with no other motors, > > solenoids, regulators, gyros or anything turned on even connected. > > > > The + cable was the one with the crimp in it. The negative cable is only > > about 18" long and connected to the frame. > > > > I have not checked the grounding strap from the engine to the firewall > > within the last two months, but will be checking that also along with the > > starter cables, ammeter cables (which I found had some "burned spots" on > > them which was hidden from view until you "unbundled" all the wiring) and > > installing an AmeriKing DC filter and Alternator filter. I've always > though > > > > Last year I replaced all the antenna cables as I found them to be bundled > > and taped to the + power cable. I also replaced all the comm antennae > > (fiberglass and cracked) with stainless steel, which helped a lot. The > > controlled field I fly out of has a "cone of static" which many complain > > about, but the FAA and FCC can't seem to isolate or do anything about, but > > rather claim it's everybody's radios... when you lift off, sometimes, the > > static is so bad you have to turn off the radios... > > > > I also replaced the alternator, voltage regulator and OV regulator plus > all > > the associated wiring as some Avionics moron had butt spliced the field > wire > > "INSIDE" the firewall cannon plug. The butt splice was broken and, of > > course, the field wire was going to ground. After 3 avionics shops > checked > > my alternator I took it out myself and found 3 diodes were bad... > > AeroElectric found that one more was bad when they replaced my alternator > > with an upgraded version with larger bearings. > > > > Yesterday as I pulled out the + battery power cable, I found all the > lights, > > strobe, electric fuel pump, and fuel sensors taped (relatively new looking > > tape) to the + power cable. Needless to say, during it's 36 year > existence, > > maintenance has always been done in FAA certified shops and done with a > very > > high level of poor quality. > > > > I honestly think this is a wiring problem relative to 36 y/o wire, but I > > won't know until I get all the wiring replaced and according to Beech > wiring > > diagram specifications. > > > > Thanks for you help and input... > > > > David J. Spencer > > Super3 > > djs(at)54Transmission.com > > > > > > ----- Original Message ----- > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > What was the reverse polarity reading? I assume since you did not give > a > > > value for another range on the VOM, that it was a Digitial Type. > > > > > > Do you have a 1 amp Current meter? From the ohmic check, that's about > the > > > current you are drawing if this is a DC load. If not, hook a 100 ohm > > > resistor in series with the + battery Cable and measure the voltage > drop > > > across the resistor. > > > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic contact) > are > > > EVERYTHING. > > > > > > However, there are frequently 2 ground levels, SIGNAL ground and POWER > > > ground. Great care must be taken when assembling your avionics to keep > > > these two seperate, and connect them only at a SINGLE POINT ground. > > > > > > It is not a bad idea to stick your head under the panel, and clean the > > > single point avionics ground to make sure the spade lugs and washers > are > > > not oxidized (high ohmic contact) > > > > > > It does not surprise me that with EXTERNAL DC power, that you do NOT > have > > > radio hum. since your do NOT have a source of noise.. > > generator/alternator, > > > motors, etc. > > > > > > You did not mention if it was the + or the - battery lead that had a > crimp > > > splice in it. If it was in the + lead. other than creating a voltage > > > drop... which would be reflected to the voltage regulator, i.e. the > > > generator/alternator would be putting out more voltage than it should > > > because it senses a Battery slightly low voltage condition. If on the > > > other hand it was on the - side. as far as the radios go, it would be > > like > > > putting a resistance between the - battery terminal and Chasis Ground. > > This > > > could conceiveably cause the noise floor to be raised...but not likely > if > > > yourGenrator/Alternator grouind is good... By the way... have to > checked > > > that to make sure you have a good & clean grounding strap from the > engine > > to > > > the firewall ?? > > > > > > Luc > > > > > > > > > ssage ----- > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > To: > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > Luc... > > > > > > > > There was approximately 11 ohms between the + & - with the correct > > > polarity > > > > hook up on the VOM. > > > > > > > > I took out the battery cable yesterday and found a split in the > > insulation > > > > about 3/8" long which had been taped over. The cable itself had been > > > > "crimped" creating a bulge and part of the internal wiring was broken > at > > > > that point. > > > > > > > > As best I could tell this open area was not laying on the skin but , > > > rather, > > > > pointing away from the skin as the cable lay on the belly of the > plane. > > > > > > > > This is being corrected with new wiring and proper attachments. > > > > > > > > I hooked the radios up to a DC power source i.e. they are isolated > from > > > > anything (except the antenna)... and the hum went away. > > > > > > > > David J. Spencer > > > > Super3 > > > > djs(at)54Transmission.com > > > > > > > > ----- Original Message ----- > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > To: > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > What resistance do you read between the battery cable and ground. > Be > > > sure > > > > > to take the measurement with the leads swapped as well as standard > > > > polarity, > > > > > i.e. red lead to + and black to -.. If you are NOT using a digital > > VOM, > > > > > then also take values in both polarities in more than one RANGE on > the > > > VOM > > > > > (active devices - diodes /transistors - are non-linear.. give you a > > good > > > > > clue if the value changes). You may have another noise suppression > > diode > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with > possibly > > a > > > > bad > > > > > capacitor in it. > > > > > > > > > > Let me know what you get. > > > > > > > > > > Luc Martini > > > > > ----- Original Message ----- > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > To: > > > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > > > > > Has anyone ever replaced the battery relay on their Beech A23-24 > > Super > > > > > III? > > > > > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt > > Voltage > > > > > > suppressor (diode) to eliminate voltage spikes flushing through > the > > > > > system. > > > > > > > > > > > > I am replacing the battery, ground and starter cables with new > > cable > > > > (AC > > > > > > grade #0 wire for the 40 amp system) and am wondering if anyone > has > > > put > > > > > in > > > > > > a > > > > > > new Aircraft grade battery relay from an aircraft supply (Spruce) > > > > source > > > > > > battery relay in place of ours. > > > > > > > > > > > > I can currently remove the battery, diode and battery rely and > get > > > > > current > > > > > > continuity (VOM) through the system from the positive cable to > the > > > > > > negative cable or any > > > > > > ground... everything is off... i.e switches, breaker etc. This > is > > > what > > > > > > some > > > > > > people think is causing a "hum" in the radios. The "hum" is > > present > > > > with > > > > > > the engine off and running the radios off a fully charged > battery. > > . > > > > > > Additionally, using the AC voltage test setup on the VOM I can > > detect > > > > > > current flow between the positive cable and ground... any ground. > > > > > > > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > > > articles > > > > > > point > > > > > > to RMI induced noise through the hull by poor shielding on the DC > > > power > > > > > > lines. > > > > > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > > > > > All comments welcomed... > > > > > > > > > > > > David J. Spencer > > > > > > Super3 > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 14, 2003
Glad to help out. I forgot to ask if there is a significant Magnetic Deviation in that area (what do they show on the maps?).. that would indicate an iron concentration in the ground that could be acting as an RF shield. The effective range of signals like VOR would also be decreased in such an area. As for Static wicks.. they never hurt, but are not all that cheap. Static discharge is more a function of humidity (altitude) than airspeed. There are 2 advantages to Static wicks in addition to possibly reducing radio noise !) is reduces galvanic corrosion..2) if you get hit by lightning, the tuffs disappear instead of a piece of your flight control surfaces. A lot of people don't realize that a plasma is not just a current, but actually moves mater. The example I like to point out are the points in an old distributor... No doubt you have noticed, that one side it builds a mountain, and the other side a pit. The mountain and the pit are always on the same side of the points. Current flows from - to +. when you open the points a plasma arc forms. The flow of electrons (which are pretty light but there are a lot of them and traveling at near the speed of light. However, at the moment you open the circuit, the total energy in the system must be equal, and you just stopped E=MC squared going that away (toward the possitive terminal) instantaneously, For things to equal out, metal (mass) must flow in the opposite direction to equalize energy state equation. Electrons are light, so it does not take many atoms of metal going much slower in the opposite direction for things to equal out, quenching the plasma. The result however is that the metal builds up over time on the - side of the points.. and that metal obviously comes from the + side. So, if your airplane is hit with lightning, the tuffs will vaporize... In military airplanes, they also provide bonding straps between the fuselage and the flight control surfaces, so that no arcing occurs in the bearing/ bolts/pins that hold them on. For the radios, you might be surprised how much you gain is Effective Range for your receivers.. you find you pick up VOR stations for example quite a few miles further out than before you spent your money and time on reducing noise sources. I take it that other people have bitched about the noise problem in your local area. With the advent of Cellphones, the general noise level have increased dramatically. That is because cellphones are a SWITCHED System. When ever you switch something on and off , you create noise. Take again for example, the old car distributor with points. If you create a PLASMA, you are radiating Radio Frequencies (Usually AM) , and as everyone knows, you splatter AM noise content all over the dial . If you SWITCH an RF signal on and off, the amount of Noise content you generate is directly proportional to the Rise and Fall time of the pulse. The faster the switch things on and off, the worse it gets. A Zero Rise and Fall time,,, which is of course impossible, would splatter equal amplitude from DC to Infinity. (and such noise could also be FM -harmonic content) So, in short, cellphones suck for radio... They have been the bane of Broadcast TV for example.. And, as you might have expected, if the Ambient Noise Level goes UP, your radio AGC compensates by turning the Signal Gain DOWN to compensate... Not nice! Do you by chance know any Ham Radio Operators in your area??? Those guys would be your best bet for finding the Noise SOURCE in the neighborhood. There is an instrument called a Field Strength Meter, which is nothing more than a Directional Antenna hooked to a TUNED Circuit, hooked up to an AM detector (diode) and that in turn to a sensitive meter movement. In short, a radio of sorts. They can go around and see where the strongest signals are coming from, and use their ham gear to see if the noise is strictly AM or possibly FM as well, and how much bandwidth is affected. THEN you can go to the guys causing the problem and threaten them with legal action if they don't clean up their act and/or go to the FAA and FCC with evidence in hand and bitch. Luc ----- Original Message ----- From: "David J. Spencer" <djs(at)54Transmission.com> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Wow... what a wealth of information... You will never know how much this is > helping and I really appreciate your input. > > First of all this is a single engine plane (1967 Beech Musketeer, 200 hp > Lycoming with fuel injection, A23-24 or Super III), so I only have one > alternator. Now to the cycling which I mentioned. The VR was a contact > type which I replaced with a Zeftronic unit. The cycling continued. I then > replaced the OV regulator with the matched Zeftronic solid state affair and > the cycling has stopped. I thought it might be one or the other as nothing > except the alternator and intercom were running when I last got fed up with > the noise. > > Turn off the alternator and the noise went away. It just made sense and the > VR & OV were both original equipment and 36+ years old. > > Thank you... You are correct for correcting me about resistance with or > without inline devices... I just wasn't thinking when I said there is no > difference as I always try to simplify the circuit to it's barest essentials > and then load on devices until I find a problem. Just my untrained > methodology. > > I will run the amperage test when I get some new battery cable installed. I > bought #4 as it met the continuous usage requirements as per the chart on > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"... HOWEVER, > the plane came with #0 wire and I am going to replace it with #0 wire. The > run from the battery to the starter solenoid is about 12 feet (12 volt > system) and then another 5 feet to the starter. The alternator is a 40 amp > unit, but my guess is that the amperage on engine start may be high enough > to warrant the heavier cable. Anyway what the hell it's just money and it > "might" prevent something I don't understand is going on... safe is better > than crispy. > > Now to the audio panel. I have a Terra TMA 230 with a marker beacon and two > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio stack. > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has three > audio grounds (connected) and one chassis ground. > > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR THE > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I also > have not put a ground on the radio trays themselves... I think I should. > > Also, my centerpoint system is a terminal block where all the posts are > connected to the same frame point as the ground. This allowed me to create > a neat little area where all the grounds (except the ones I just mentioned) > are located. The intercom requires insulating all the headset jacks (with > isolation washers) and using the centerpoint ground. > > Now to the Cone of Static... below is a diagram of the airport in > relationship to some 1600' AGL radio, TV & Microwave transmission towers > which are South of the field about 5 miles. The airport is directly between > the towers and Downtown Dallas Texas. Is it possible that the towers could > be transmitting a directional signal toward downtown? > > > ++++ > > +++++ Radio Transmission towers (~15 @ 1600' AGL) > > +++++ > > about > five miles to towers > > > | > | > | Runway (17/35) > | > | > > > about three miles > > DOWNTOWN DALLAS TEXAS > > As for large metallic structures...there are two hangars built by Howard > Hughes for something really big right on the 17/35 runway. Other than that > there is an FBI/U.S. Customs helicopter hangar (which tends to be rather a > secretive place) on the South end of the field and a medium sized strip mall > just across a highway to the South. There is also a six story Wells Fargo > Bank down by the FBI. > > There is a National Guard Armory on the West side of the field which, I > believe has some radio antennae sticking up in the wooded area adjacent to > it... I'll check on the way home. My wife (she's a pilot also) says she > thinks the bank tower has dish antennae on it... either the bank or the FBI. > That's her side of the plane so I never look out there, because I don't want > to see what she's going to hit, and will check on it on way home. > > The antennas are well grounded, but are on the aft slope of the top of the > fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF > which required triaxial cable I changed EVERYTHING to triaxial as it just > seemed the logical thing to do. > > They are too close together (about 2 feet apart), but are about 5 feet aft > of the Loran antenna. The transponder is under the foward fuselage (blade > type) and the ADF & marker beacon are on the bottom aft fuselage. The > aftmost comm antenna is very close to the vertical stabilizer which has an > ABS plastic shroud on the leading edge to affect airflow. I never thought > much about the static from plastic as all I've read indicates that our plane > is too slow... we cruise at ~145-150 mph with take-off and climb at 90-100 > mph. Should I install some static wicks? > > We only get this static garbage at this airport... no where else we have > flown has given us any problems and we have been into some strange places > like the Arizona & New Mexico desert and along the U.S./ Mexico border. > > You will never know how much you are helping... I tend to be a rather > tenacious person and want very much to understand as much as possible about > what is going on and how to eliminate it... if possible. > > David > > > ----- Original Message ----- > From: "Martini Luc J.R." <martini(at)foxinternet.net> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Hello again > > > > There can be a very considerable difference in resitance readings of a VOM > > for forward v. reverse polarity if you have an "Active Device" in the > > circuit... i.e. a Diode, or a Transistor. Looking from the battery, you > > could be looking at several of these, (diodes or transistors) which are > > used for noise suppression, voltage spike protection, even internally in > a > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated by a > > circuit breaker. > > > > If there is No change as you indicated, that simply verifies that you > likely > > DO NOT have an Active Device in the Battery Bus Circuit, since Active > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is > typically > > MUCH higher in one polarity than the other. > > > > If your VOM has a 1 amp direct reading capability, the way to proceed is > to > > disconnected the + lead from the battery. Set your VOM to DC CURRENT > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in SERIES > > with the battery, i.e., VOM - lead to battery cable (where the LOAD is), > and > > + lead to the battery + lead (Current Source). > > > > The reading you will get will be in either MILLIAMPS (ma) or AMPS (A).. > > depending on your meter...if the scale is calibrated in (ma), move the > > decimal place to the right 3 spaces (X 1000) for (amps) > > > > If you are using your fully charged aircraft battery,. you should get > 1.09 > > Amps showing on the meter.: > > > > 12 VDC/11 OHMS = 1.09 AMPS. > > > > Note that if you use external power the voltage might be higher, up to 14 > > volts.. that might damage your VOM since that is 1.3 Amps. > > > > You may have done this already according to your note, but you read the > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter is > > different, I have no way of knowing what the .245 you referred to really > is. > > > > The nice thing about using a CURRENT METER is that you can leave it hooked > > up and go disconnect various things that power goes to, i.e voltage > > regulators, bulkhead connectors, circuit breakers, etc. and with a quick > > check see if the current dropped to ZERO.... BINGO... your problem is in > > THAT CIRCUIT. > > > > As to your question about Avionics Signal and Power Grounds. NO, they > MUST > > be connected together at ONE and ONLY one place for noise immunity... > also > > helps with lighning protection. Signal ground is not the same as AUDIO > > ground. > > > > That is not to say that Avionics Shops do things right... as you have > found > > out. > > > > There is one other thing I should tell you about. Audio Panels are an > even > > MORE complicated item. In Audio Panels, they may have as many as 2 MORE > > types of Grounds. King (KMA-24) is famous for this. You have to Isolate > the > > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot > audio > > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND. > > These suckers can be real bears, and the source of Noise PICKUP (from > > external sources such as motors, sparks (like bad shielding on spark plug > > wires) and even external to the aircraft.. industrial sources. > > > > The Noise Zone you mention is intriguing. There are two ways of looking > at > > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2), > that > > there exists a SHIELD from radiation. > > > > I believe the first is what everybody has been focused on. However, the > > second is just as likely if not more so. For example, if there is a > > significant magnetic disturbance in the area, or a very large metalic > > structure in the area, or a hill with a lot of iron content.. etc. etc. > > these can shield the background RF Noise Level The Automatic Gain > Control > > (AGC) circuits in you radios, and/or audio panel, would compensate by > > INCREASING the GAIN... that would result in audio STATIC...exactly like > what > > you get when listening to your AM radio in the car when you drive through > a > > tunnel. > > > > I got the point you made that you had EVERYTHING disconnected except the > > Battery and the Avionics DC bus and of course the radios that power them.. > > One thing you should also do, is turn of your Transponder. Also, if the > > Antenna Coax for the Transponder and the DME (if you have one) are run > > parallel with other wiring bundles, that can be a source of severe static. > > I always use Double Shielded Coax for these devices... some Av Shops do > > not... and if I have to cross a wire bundle, I do it at as close to 90 > > degrees as I can.(the Electric and Magnetic Fields no not couple to the > > other cable when; you do that) Obviously it pays to keep these Coax > leads > > as short as possible (but must generally be no shorter than 3 feet (1/2 > wave > > length). > > > > Another general practice to follow is good GROUND PLANES for the antennas. > > What that means generally, is as much flat metal around the antenna as > your > > airplane and avionics can afford; keep radiating elements like DME and > > Transponder seperated by 6' from each other.. as well as from very low > > signal sources like LORAN, GPS...Keep the Comm antenna away from those as > > well... and strangely enough, keep these well away and UP-STREAM > > (airstream) from non-electrically conductive surfaces such as Plexiglass, > > Fiberglass etc. (these create static electricity that can couple the > > discharge via inonizatiotion of the airstream) Then, have a Good Low > ohmic > > contact for the antennas. That means cleaning away all paint where the > > antenna mounts, and Alodining the area. and on the INSIDE of the > airplane, > > make sure that your have a good clean contact in like fashion for the > > antenna mounting nuts/bolts. > > > > I just received another e-mail from you... about the odd charging habits > of > > your airplane. Keep in mind, that a fully charged battery is 12 VDC. > > However, your voltage regulator puts out between 13.5 and 14.00 volts > > depending on the current draw, and the internal setting of you voltage > > regulator. You would be surprised at the variation in "Idling Current" > from > > one Regulator to the next. So, it does NOT surprise me that even after > > starting your engines with a full battery, that they do a little chargin > for > > a while. What DOES surprise me is the CYCLING you mentioned. That was > > common in the old days of RELAY type voltage regulagtors, but NOT for > Solid > > state Alternator Regulators. > > > > Do you have some sort of switching arangement for left/right engine > > alternators? > > > > Luc > > > > > > ----- Original Message ----- > > From: "David J. Spencer" <djs(at)54Transmission.com> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > Luc... > > > > > > The resistance didn't change with a reverse in polarity... it rarely > does. > > > > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran a > > check > > > with the +/- cables I got .245 volt flow in either direction. > > > > > > You raise an interesting point about the two different types of > grounds... > > > power and audio. Both are separated in the wiring harness, but > connected > > to > > > the same center point ground. Should there be two center point grounds? > > > > > > Everything is very clean as I just rebuilt the wiring harness. I have > had > > > it out twice and rechecked for faulty wiring or shielding touching the > > > center wire and it checks out just fine. > > > > > > With the DC power source hooked directly to the power cable (I come off > > the > > > power bus with one power cable to the audio panel, 2 NavComs, > transponder, > > > ADF and intercom though another set of breakers) to the radio stack, the > > > only thing I eliminated was the battery and the associated wiring... all > > > other noise sources (motors, alternator, gyros, etc.) were always off. > I > > > was getting the hum just off the battery power with no other motors, > > > solenoids, regulators, gyros or anything turned on even connected. > > > > > > The + cable was the one with the crimp in it. The negative cable is > only > > > about 18" long and connected to the frame. > > > > > > I have not checked the grounding strap from the engine to the firewall > > > within the last two months, but will be checking that also along with > the > > > starter cables, ammeter cables (which I found had some "burned spots" on > > > them which was hidden from view until you "unbundled" all the wiring) > and > > > installing an AmeriKing DC filter and Alternator filter. I've always > > though > > > > > > Last year I replaced all the antenna cables as I found them to be > bundled > > > and taped to the + power cable. I also replaced all the comm antennae > > > (fiberglass and cracked) with stainless steel, which helped a lot. The > > > controlled field I fly out of has a "cone of static" which many complain > > > about, but the FAA and FCC can't seem to isolate or do anything about, > but > > > rather claim it's everybody's radios... when you lift off, sometimes, > the > > > static is so bad you have to turn off the radios... > > > > > > I also replaced the alternator, voltage regulator and OV regulator plus > > all > > > the associated wiring as some Avionics moron had butt spliced the field > > wire > > > "INSIDE" the firewall cannon plug. The butt splice was broken and, of > > > course, the field wire was going to ground. After 3 avionics shops > > checked > > > my alternator I took it out myself and found 3 diodes were bad... > > > AeroElectric found that one more was bad when they replaced my > alternator > > > with an upgraded version with larger bearings. > > > > > > Yesterday as I pulled out the + battery power cable, I found all the > > lights, > > > strobe, electric fuel pump, and fuel sensors taped (relatively new > looking > > > tape) to the + power cable. Needless to say, during it's 36 year > > existence, > > > maintenance has always been done in FAA certified shops and done with a > > very > > > high level of poor quality. > > > > > > I honestly think this is a wiring problem relative to 36 y/o wire, but I > > > won't know until I get all the wiring replaced and according to Beech > > wiring > > > diagram specifications. > > > > > > Thanks for you help and input... > > > > > > David J. Spencer > > > Super3 > > > djs(at)54Transmission.com > > > > > > > > > ----- Original Message ----- > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > To: > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > What was the reverse polarity reading? I assume since you did not > give > > a > > > > value for another range on the VOM, that it was a Digitial Type. > > > > > > > > Do you have a 1 amp Current meter? From the ohmic check, that's about > > the > > > > current you are drawing if this is a DC load. If not, hook a 100 ohm > > > > resistor in series with the + battery Cable and measure the voltage > > drop > > > > across the resistor. > > > > > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic contact) > > are > > > > EVERYTHING. > > > > > > > > However, there are frequently 2 ground levels, SIGNAL ground and POWER > > > > ground. Great care must be taken when assembling your avionics to > keep > > > > these two seperate, and connect them only at a SINGLE POINT ground. > > > > > > > > It is not a bad idea to stick your head under the panel, and clean the > > > > single point avionics ground to make sure the spade lugs and washers > > are > > > > not oxidized (high ohmic contact) > > > > > > > > It does not surprise me that with EXTERNAL DC power, that you do NOT > > have > > > > radio hum. since your do NOT have a source of noise.. > > > generator/alternator, > > > > motors, etc. > > > > > > > > You did not mention if it was the + or the - battery lead that had a > > crimp > > > > splice in it. If it was in the + lead. other than creating a voltage > > > > drop... which would be reflected to the voltage regulator, i.e. the > > > > generator/alternator would be putting out more voltage than it should > > > > because it senses a Battery slightly low voltage condition. If on > the > > > > other hand it was on the - side. as far as the radios go, it would be > > > like > > > > putting a resistance between the - battery terminal and Chasis Ground. > > > This > > > > could conceiveably cause the noise floor to be raised...but not likely > > if > > > > yourGenrator/Alternator grouind is good... By the way... have to > > checked > > > > that to make sure you have a good & clean grounding strap from the > > engine > > > to > > > > the firewall ?? > > > > > > > > Luc > > > > > > > > > > > > ssage ----- > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > To: > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > Luc... > > > > > > > > > > There was approximately 11 ohms between the + & - with the correct > > > > polarity > > > > > hook up on the VOM. > > > > > > > > > > I took out the battery cable yesterday and found a split in the > > > insulation > > > > > about 3/8" long which had been taped over. The cable itself had > been > > > > > "crimped" creating a bulge and part of the internal wiring was > broken > > at > > > > > that point. > > > > > > > > > > As best I could tell this open area was not laying on the skin but , > > > > rather, > > > > > pointing away from the skin as the cable lay on the belly of the > > plane. > > > > > > > > > > This is being corrected with new wiring and proper attachments. > > > > > > > > > > I hooked the radios up to a DC power source i.e. they are isolated > > from > > > > > anything (except the antenna)... and the hum went away. > > > > > > > > > > David J. Spencer > > > > > Super3 > > > > > djs(at)54Transmission.com > > > > > > > > > > ----- Original Message ----- > > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > > To: > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > What resistance do you read between the battery cable and ground. > > Be > > > > sure > > > > > > to take the measurement with the leads swapped as well as standard > > > > > polarity, > > > > > > i.e. red lead to + and black to -.. If you are NOT using a > digital > > > VOM, > > > > > > then also take values in both polarities in more than one RANGE on > > the > > > > VOM > > > > > > (active devices - diodes /transistors - are non-linear.. give you > a > > > good > > > > > > clue if the value changes). You may have another noise suppression > > > diode > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with > > possibly > > > a > > > > > bad > > > > > > capacitor in it. > > > > > > > > > > > > Let me know what you get. > > > > > > > > > > > > Luc Martini > > > > > > ----- Original Message ----- > > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > > To: > > > > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > > > > > > > Has anyone ever replaced the battery relay on their Beech A23-24 > > > Super > > > > > > III? > > > > > > > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt > > > Voltage > > > > > > > suppressor (diode) to eliminate voltage spikes flushing through > > the > > > > > > system. > > > > > > > > > > > > > > I am replacing the battery, ground and starter cables with new > > > cable > > > > > (AC > > > > > > > grade #0 wire for the 40 amp system) and am wondering if anyone > > has > > > > put > > > > > > in > > > > > > > a > > > > > > > new Aircraft grade battery relay from an aircraft supply > (Spruce) > > > > > source > > > > > > > battery relay in place of ours. > > > > > > > > > > > > > > I can currently remove the battery, diode and battery rely and > > get > > > > > > current > > > > > > > continuity (VOM) through the system from the positive cable to > > the > > > > > > > negative cable or any > > > > > > > ground... everything is off... i.e switches, breaker etc. This > > is > > > > what > > > > > > > some > > > > > > > people think is causing a "hum" in the radios. The "hum" is > > > present > > > > > with > > > > > > > the engine off and running the radios off a fully charged > > battery. > > > . > > > > > > > Additionally, using the AC voltage test setup on the VOM I can > > > detect > > > > > > > current flow between the positive cable and ground... any > ground. > > > > > > > > > > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > > > > articles > > > > > > > point > > > > > > > to RMI induced noise through the hull by poor shielding on the > DC > > > > power > > > > > > > lines. > > > > > > > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > > > > > > > All comments welcomed... > > > > > > > > > > > > > > David J. Spencer > > > > > > > Super3 > > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 14, 2003
Hi again I forget to mention something about what you said you used for Coax. Triax is of course a Double Shielded form of Coax, and has the proper 50 Ohm impedance just like RG-58 (which also comes in a doble shielded variety). However, it has an additional insulation layer between the first and second shield. Obviously, that makes the coax larger in diameter and heavier. The cable was actually designed for use on Cable TV systems. By putting an insulator between the shields, they not only kept the better noise immunity that double shielding provided, but more importantly, could use the shields as CONDUCTORS the send power to the INLINE AMPS that the cables systems need to install every 1/2 mile or so to compensate for line losses i.e, one shield carried a +28VDC and the other was the Power as well as Signal Ground.. cute eh? The problem in airplanes with TRIAX, is that they are a BITCH to terminate at coaxial connectors properly. The greatest problem is because they used plastic that melt rather readily at soldering iron temperatures, while the better forms of RG-58 used nylon center conductors. And, stripping that 2nd layer of plastic so that you can join the braids before jamming them into a connector can get REALLY MESSY and at the very least result in one hell of a lot of serious cussing. Luc ----- Original Message ----- From: "David J. Spencer" <djs(at)54Transmission.com> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Wow... what a wealth of information... You will never know how much this is > helping and I really appreciate your input. > > First of all this is a single engine plane (1967 Beech Musketeer, 200 hp > Lycoming with fuel injection, A23-24 or Super III), so I only have one > alternator. Now to the cycling which I mentioned. The VR was a contact > type which I replaced with a Zeftronic unit. The cycling continued. I then > replaced the OV regulator with the matched Zeftronic solid state affair and > the cycling has stopped. I thought it might be one or the other as nothing > except the alternator and intercom were running when I last got fed up with > the noise. > > Turn off the alternator and the noise went away. It just made sense and the > VR & OV were both original equipment and 36+ years old. > > Thank you... You are correct for correcting me about resistance with or > without inline devices... I just wasn't thinking when I said there is no > difference as I always try to simplify the circuit to it's barest essentials > and then load on devices until I find a problem. Just my untrained > methodology. > > I will run the amperage test when I get some new battery cable installed. I > bought #4 as it met the continuous usage requirements as per the chart on > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"... HOWEVER, > the plane came with #0 wire and I am going to replace it with #0 wire. The > run from the battery to the starter solenoid is about 12 feet (12 volt > system) and then another 5 feet to the starter. The alternator is a 40 amp > unit, but my guess is that the amperage on engine start may be high enough > to warrant the heavier cable. Anyway what the hell it's just money and it > "might" prevent something I don't understand is going on... safe is better > than crispy. > > Now to the audio panel. I have a Terra TMA 230 with a marker beacon and two > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio stack. > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has three > audio grounds (connected) and one chassis ground. > > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR THE > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I also > have not put a ground on the radio trays themselves... I think I should. > > Also, my centerpoint system is a terminal block where all the posts are > connected to the same frame point as the ground. This allowed me to create > a neat little area where all the grounds (except the ones I just mentioned) > are located. The intercom requires insulating all the headset jacks (with > isolation washers) and using the centerpoint ground. > > Now to the Cone of Static... below is a diagram of the airport in > relationship to some 1600' AGL radio, TV & Microwave transmission towers > which are South of the field about 5 miles. The airport is directly between > the towers and Downtown Dallas Texas. Is it possible that the towers could > be transmitting a directional signal toward downtown? > > > ++++ > > +++++ Radio Transmission towers (~15 @ 1600' AGL) > > +++++ > > about > five miles to towers > > > | > | > | Runway (17/35) > | > | > > > about three miles > > DOWNTOWN DALLAS TEXAS > > As for large metallic structures...there are two hangars built by Howard > Hughes for something really big right on the 17/35 runway. Other than that > there is an FBI/U.S. Customs helicopter hangar (which tends to be rather a > secretive place) on the South end of the field and a medium sized strip mall > just across a highway to the South. There is also a six story Wells Fargo > Bank down by the FBI. > > There is a National Guard Armory on the West side of the field which, I > believe has some radio antennae sticking up in the wooded area adjacent to > it... I'll check on the way home. My wife (she's a pilot also) says she > thinks the bank tower has dish antennae on it... either the bank or the FBI. > That's her side of the plane so I never look out there, because I don't want > to see what she's going to hit, and will check on it on way home. > > The antennas are well grounded, but are on the aft slope of the top of the > fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF > which required triaxial cable I changed EVERYTHING to triaxial as it just > seemed the logical thing to do. > > They are too close together (about 2 feet apart), but are about 5 feet aft > of the Loran antenna. The transponder is under the foward fuselage (blade > type) and the ADF & marker beacon are on the bottom aft fuselage. The > aftmost comm antenna is very close to the vertical stabilizer which has an > ABS plastic shroud on the leading edge to affect airflow. I never thought > much about the static from plastic as all I've read indicates that our plane > is too slow... we cruise at ~145-150 mph with take-off and climb at 90-100 > mph. Should I install some static wicks? > > We only get this static garbage at this airport... no where else we have > flown has given us any problems and we have been into some strange places > like the Arizona & New Mexico desert and along the U.S./ Mexico border. > > You will never know how much you are helping... I tend to be a rather > tenacious person and want very much to understand as much as possible about > what is going on and how to eliminate it... if possible. > > David > > > ----- Original Message ----- > From: "Martini Luc J.R." <martini(at)foxinternet.net> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Hello again > > > > There can be a very considerable difference in resitance readings of a VOM > > for forward v. reverse polarity if you have an "Active Device" in the > > circuit... i.e. a Diode, or a Transistor. Looking from the battery, you > > could be looking at several of these, (diodes or transistors) which are > > used for noise suppression, voltage spike protection, even internally in > a > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated by a > > circuit breaker. > > > > If there is No change as you indicated, that simply verifies that you > likely > > DO NOT have an Active Device in the Battery Bus Circuit, since Active > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is > typically > > MUCH higher in one polarity than the other. > > > > If your VOM has a 1 amp direct reading capability, the way to proceed is > to > > disconnected the + lead from the battery. Set your VOM to DC CURRENT > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in SERIES > > with the battery, i.e., VOM - lead to battery cable (where the LOAD is), > and > > + lead to the battery + lead (Current Source). > > > > The reading you will get will be in either MILLIAMPS (ma) or AMPS (A).. > > depending on your meter...if the scale is calibrated in (ma), move the > > decimal place to the right 3 spaces (X 1000) for (amps) > > > > If you are using your fully charged aircraft battery,. you should get > 1.09 > > Amps showing on the meter.: > > > > 12 VDC/11 OHMS = 1.09 AMPS. > > > > Note that if you use external power the voltage might be higher, up to 14 > > volts.. that might damage your VOM since that is 1.3 Amps. > > > > You may have done this already according to your note, but you read the > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter is > > different, I have no way of knowing what the .245 you referred to really > is. > > > > The nice thing about using a CURRENT METER is that you can leave it hooked > > up and go disconnect various things that power goes to, i.e voltage > > regulators, bulkhead connectors, circuit breakers, etc. and with a quick > > check see if the current dropped to ZERO.... BINGO... your problem is in > > THAT CIRCUIT. > > > > As to your question about Avionics Signal and Power Grounds. NO, they > MUST > > be connected together at ONE and ONLY one place for noise immunity... > also > > helps with lighning protection. Signal ground is not the same as AUDIO > > ground. > > > > That is not to say that Avionics Shops do things right... as you have > found > > out. > > > > There is one other thing I should tell you about. Audio Panels are an > even > > MORE complicated item. In Audio Panels, they may have as many as 2 MORE > > types of Grounds. King (KMA-24) is famous for this. You have to Isolate > the > > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot > audio > > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND. > > These suckers can be real bears, and the source of Noise PICKUP (from > > external sources such as motors, sparks (like bad shielding on spark plug > > wires) and even external to the aircraft.. industrial sources. > > > > The Noise Zone you mention is intriguing. There are two ways of looking > at > > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2), > that > > there exists a SHIELD from radiation. > > > > I believe the first is what everybody has been focused on. However, the > > second is just as likely if not more so. For example, if there is a > > significant magnetic disturbance in the area, or a very large metalic > > structure in the area, or a hill with a lot of iron content.. etc. etc. > > these can shield the background RF Noise Level The Automatic Gain > Control > > (AGC) circuits in you radios, and/or audio panel, would compensate by > > INCREASING the GAIN... that would result in audio STATIC...exactly like > what > > you get when listening to your AM radio in the car when you drive through > a > > tunnel. > > > > I got the point you made that you had EVERYTHING disconnected except the > > Battery and the Avionics DC bus and of course the radios that power them.. > > One thing you should also do, is turn of your Transponder. Also, if the > > Antenna Coax for the Transponder and the DME (if you have one) are run > > parallel with other wiring bundles, that can be a source of severe static. > > I always use Double Shielded Coax for these devices... some Av Shops do > > not... and if I have to cross a wire bundle, I do it at as close to 90 > > degrees as I can.(the Electric and Magnetic Fields no not couple to the > > other cable when; you do that) Obviously it pays to keep these Coax > leads > > as short as possible (but must generally be no shorter than 3 feet (1/2 > wave > > length). > > > > Another general practice to follow is good GROUND PLANES for the antennas. > > What that means generally, is as much flat metal around the antenna as > your > > airplane and avionics can afford; keep radiating elements like DME and > > Transponder seperated by 6' from each other.. as well as from very low > > signal sources like LORAN, GPS...Keep the Comm antenna away from those as > > well... and strangely enough, keep these well away and UP-STREAM > > (airstream) from non-electrically conductive surfaces such as Plexiglass, > > Fiberglass etc. (these create static electricity that can couple the > > discharge via inonizatiotion of the airstream) Then, have a Good Low > ohmic > > contact for the antennas. That means cleaning away all paint where the > > antenna mounts, and Alodining the area. and on the INSIDE of the > airplane, > > make sure that your have a good clean contact in like fashion for the > > antenna mounting nuts/bolts. > > > > I just received another e-mail from you... about the odd charging habits > of > > your airplane. Keep in mind, that a fully charged battery is 12 VDC. > > However, your voltage regulator puts out between 13.5 and 14.00 volts > > depending on the current draw, and the internal setting of you voltage > > regulator. You would be surprised at the variation in "Idling Current" > from > > one Regulator to the next. So, it does NOT surprise me that even after > > starting your engines with a full battery, that they do a little chargin > for > > a while. What DOES surprise me is the CYCLING you mentioned. That was > > common in the old days of RELAY type voltage regulagtors, but NOT for > Solid > > state Alternator Regulators. > > > > Do you have some sort of switching arangement for left/right engine > > alternators? > > > > Luc > > > > > > ----- Original Message ----- > > From: "David J. Spencer" <djs(at)54Transmission.com> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > Luc... > > > > > > The resistance didn't change with a reverse in polarity... it rarely > does. > > > > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran a > > check > > > with the +/- cables I got .245 volt flow in either direction. > > > > > > You raise an interesting point about the two different types of > grounds... > > > power and audio. Both are separated in the wiring harness, but > connected > > to > > > the same center point ground. Should there be two center point grounds? > > > > > > Everything is very clean as I just rebuilt the wiring harness. I have > had > > > it out twice and rechecked for faulty wiring or shielding touching the > > > center wire and it checks out just fine. > > > > > > With the DC power source hooked directly to the power cable (I come off > > the > > > power bus with one power cable to the audio panel, 2 NavComs, > transponder, > > > ADF and intercom though another set of breakers) to the radio stack, the > > > only thing I eliminated was the battery and the associated wiring... all > > > other noise sources (motors, alternator, gyros, etc.) were always off. > I > > > was getting the hum just off the battery power with no other motors, > > > solenoids, regulators, gyros or anything turned on even connected. > > > > > > The + cable was the one with the crimp in it. The negative cable is > only > > > about 18" long and connected to the frame. > > > > > > I have not checked the grounding strap from the engine to the firewall > > > within the last two months, but will be checking that also along with > the > > > starter cables, ammeter cables (which I found had some "burned spots" on > > > them which was hidden from view until you "unbundled" all the wiring) > and > > > installing an AmeriKing DC filter and Alternator filter. I've always > > though > > > > > > Last year I replaced all the antenna cables as I found them to be > bundled > > > and taped to the + power cable. I also replaced all the comm antennae > > > (fiberglass and cracked) with stainless steel, which helped a lot. The > > > controlled field I fly out of has a "cone of static" which many complain > > > about, but the FAA and FCC can't seem to isolate or do anything about, > but > > > rather claim it's everybody's radios... when you lift off, sometimes, > the > > > static is so bad you have to turn off the radios... > > > > > > I also replaced the alternator, voltage regulator and OV regulator plus > > all > > > the associated wiring as some Avionics moron had butt spliced the field > > wire > > > "INSIDE" the firewall cannon plug. The butt splice was broken and, of > > > course, the field wire was going to ground. After 3 avionics shops > > checked > > > my alternator I took it out myself and found 3 diodes were bad... > > > AeroElectric found that one more was bad when they replaced my > alternator > > > with an upgraded version with larger bearings. > > > > > > Yesterday as I pulled out the + battery power cable, I found all the > > lights, > > > strobe, electric fuel pump, and fuel sensors taped (relatively new > looking > > > tape) to the + power cable. Needless to say, during it's 36 year > > existence, > > > maintenance has always been done in FAA certified shops and done with a > > very > > > high level of poor quality. > > > > > > I honestly think this is a wiring problem relative to 36 y/o wire, but I > > > won't know until I get all the wiring replaced and according to Beech > > wiring > > > diagram specifications. > > > > > > Thanks for you help and input... > > > > > > David J. Spencer > > > Super3 > > > djs(at)54Transmission.com > > > > > > > > > ----- Original Message ----- > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > To: > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > What was the reverse polarity reading? I assume since you did not > give > > a > > > > value for another range on the VOM, that it was a Digitial Type. > > > > > > > > Do you have a 1 amp Current meter? From the ohmic check, that's about > > the > > > > current you are drawing if this is a DC load. If not, hook a 100 ohm > > > > resistor in series with the + battery Cable and measure the voltage > > drop > > > > across the resistor. > > > > > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic contact) > > are > > > > EVERYTHING. > > > > > > > > However, there are frequently 2 ground levels, SIGNAL ground and POWER > > > > ground. Great care must be taken when assembling your avionics to > keep > > > > these two seperate, and connect them only at a SINGLE POINT ground. > > > > > > > > It is not a bad idea to stick your head under the panel, and clean the > > > > single point avionics ground to make sure the spade lugs and washers > > are > > > > not oxidized (high ohmic contact) > > > > > > > > It does not surprise me that with EXTERNAL DC power, that you do NOT > > have > > > > radio hum. since your do NOT have a source of noise.. > > > generator/alternator, > > > > motors, etc. > > > > > > > > You did not mention if it was the + or the - battery lead that had a > > crimp > > > > splice in it. If it was in the + lead. other than creating a voltage > > > > drop... which would be reflected to the voltage regulator, i.e. the > > > > generator/alternator would be putting out more voltage than it should > > > > because it senses a Battery slightly low voltage condition. If on > the > > > > other hand it was on the - side. as far as the radios go, it would be > > > like > > > > putting a resistance between the - battery terminal and Chasis Ground. > > > This > > > > could conceiveably cause the noise floor to be raised...but not likely > > if > > > > yourGenrator/Alternator grouind is good... By the way... have to > > checked > > > > that to make sure you have a good & clean grounding strap from the > > engine > > > to > > > > the firewall ?? > > > > > > > > Luc > > > > > > > > > > > > ssage ----- > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > To: > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > Luc... > > > > > > > > > > There was approximately 11 ohms between the + & - with the correct > > > > polarity > > > > > hook up on the VOM. > > > > > > > > > > I took out the battery cable yesterday and found a split in the > > > insulation > > > > > about 3/8" long which had been taped over. The cable itself had > been > > > > > "crimped" creating a bulge and part of the internal wiring was > broken > > at > > > > > that point. > > > > > > > > > > As best I could tell this open area was not laying on the skin but , > > > > rather, > > > > > pointing away from the skin as the cable lay on the belly of the > > plane. > > > > > > > > > > This is being corrected with new wiring and proper attachments. > > > > > > > > > > I hooked the radios up to a DC power source i.e. they are isolated > > from > > > > > anything (except the antenna)... and the hum went away. > > > > > > > > > > David J. Spencer > > > > > Super3 > > > > > djs(at)54Transmission.com > > > > > > > > > > ----- Original Message ----- > > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > > To: > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > What resistance do you read between the battery cable and ground. > > Be > > > > sure > > > > > > to take the measurement with the leads swapped as well as standard > > > > > polarity, > > > > > > i.e. red lead to + and black to -.. If you are NOT using a > digital > > > VOM, > > > > > > then also take values in both polarities in more than one RANGE on > > the > > > > VOM > > > > > > (active devices - diodes /transistors - are non-linear.. give you > a > > > good > > > > > > clue if the value changes). You may have another noise suppression > > > diode > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with > > possibly > > > a > > > > > bad > > > > > > capacitor in it. > > > > > > > > > > > > Let me know what you get. > > > > > > > > > > > > Luc Martini > > > > > > ----- Original Message ----- > > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > > To: > > > > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > > > > > > > Has anyone ever replaced the battery relay on their Beech A23-24 > > > Super > > > > > > III? > > > > > > > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt > > > Voltage > > > > > > > suppressor (diode) to eliminate voltage spikes flushing through > > the > > > > > > system. > > > > > > > > > > > > > > I am replacing the battery, ground and starter cables with new > > > cable > > > > > (AC > > > > > > > grade #0 wire for the 40 amp system) and am wondering if anyone > > has > > > > put > > > > > > in > > > > > > > a > > > > > > > new Aircraft grade battery relay from an aircraft supply > (Spruce) > > > > > source > > > > > > > battery relay in place of ours. > > > > > > > > > > > > > > I can currently remove the battery, diode and battery rely and > > get > > > > > > current > > > > > > > continuity (VOM) through the system from the positive cable to > > the > > > > > > > negative cable or any > > > > > > > ground... everything is off... i.e switches, breaker etc. This > > is > > > > what > > > > > > > some > > > > > > > people think is causing a "hum" in the radios. The "hum" is > > > present > > > > > with > > > > > > > the engine off and running the radios off a fully charged > > battery. > > > . > > > > > > > Additionally, using the AC voltage test setup on the VOM I can > > > detect > > > > > > > current flow between the positive cable and ground... any > ground. > > > > > > > > > > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > > > > articles > > > > > > > point > > > > > > > to RMI induced noise through the hull by poor shielding on the > DC > > > > power > > > > > > > lines. > > > > > > > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > > > > > > > All comments welcomed... > > > > > > > > > > > > > > David J. Spencer > > > > > > > Super3 > > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 15, 2003
Luc... You are right about the Triax and terminating it at the BNC... and all this time I thought it was just my technique or lack of it. David ----- Original Message ----- From: "Martini Luc J.R." <martini(at)foxinternet.net> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Hi again > I forget to mention something about what you said you used for Coax. Triax > is of course a Double Shielded form of Coax, and has the proper 50 Ohm > impedance just like RG-58 (which also comes in a doble shielded variety). > However, it has an additional insulation layer between the first and second > shield. Obviously, that makes the coax larger in diameter and heavier. > The cable was actually designed for use on Cable TV systems. By putting an > insulator between the shields, they not only kept the better noise immunity > that double shielding provided, but more importantly, could use the shields > as CONDUCTORS the send power to the INLINE AMPS that the cables systems need > to install every 1/2 mile or so to compensate for line losses i.e, one > shield carried a +28VDC and the other was the Power as well as Signal > Ground.. cute eh? > > The problem in airplanes with TRIAX, is that they are a BITCH to terminate > at coaxial connectors properly. The greatest problem is because they used > plastic that melt rather readily at soldering iron temperatures, while the > better forms of RG-58 used nylon center conductors. And, stripping that > 2nd layer of plastic so that you can join the braids before jamming them > into a connector can get REALLY MESSY and at the very least result in one > hell of a lot of serious cussing. > > Luc > ----- Original Message ----- > From: "David J. Spencer" <djs(at)54Transmission.com> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Wow... what a wealth of information... You will never know how much this > is > > helping and I really appreciate your input. > > > > First of all this is a single engine plane (1967 Beech Musketeer, 200 hp > > Lycoming with fuel injection, A23-24 or Super III), so I only have one > > alternator. Now to the cycling which I mentioned. The VR was a contact > > type which I replaced with a Zeftronic unit. The cycling continued. I > then > > replaced the OV regulator with the matched Zeftronic solid state affair > and > > the cycling has stopped. I thought it might be one or the other as > nothing > > except the alternator and intercom were running when I last got fed up > with > > the noise. > > > > Turn off the alternator and the noise went away. It just made sense and > the > > VR & OV were both original equipment and 36+ years old. > > > > Thank you... You are correct for correcting me about resistance with or > > without inline devices... I just wasn't thinking when I said there is no > > difference as I always try to simplify the circuit to it's barest > essentials > > and then load on devices until I find a problem. Just my untrained > > methodology. > > > > I will run the amperage test when I get some new battery cable installed. > I > > bought #4 as it met the continuous usage requirements as per the chart on > > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"... > HOWEVER, > > the plane came with #0 wire and I am going to replace it with #0 wire. > The > > run from the battery to the starter solenoid is about 12 feet (12 volt > > system) and then another 5 feet to the starter. The alternator is a 40 > amp > > unit, but my guess is that the amperage on engine start may be high enough > > to warrant the heavier cable. Anyway what the hell it's just money and it > > "might" prevent something I don't understand is going on... safe is better > > than crispy. > > > > Now to the audio panel. I have a Terra TMA 230 with a marker beacon and > two > > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio > stack. > > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics > > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has > three > > audio grounds (connected) and one chassis ground. > > > > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR > THE > > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I also > > have not put a ground on the radio trays themselves... I think I should. > > > > Also, my centerpoint system is a terminal block where all the posts are > > connected to the same frame point as the ground. This allowed me to > create > > a neat little area where all the grounds (except the ones I just > mentioned) > > are located. The intercom requires insulating all the headset jacks (with > > isolation washers) and using the centerpoint ground. > > > > Now to the Cone of Static... below is a diagram of the airport in > > relationship to some 1600' AGL radio, TV & Microwave transmission towers > > which are South of the field about 5 miles. The airport is directly > between > > the towers and Downtown Dallas Texas. Is it possible that the towers > could > > be transmitting a directional signal toward downtown? > > > > > > ++++ > > > > +++++ Radio Transmission towers (~15 @ 1600' AGL) > > > > +++++ > > > > > about > > five miles to towers > > > > > > | > > | > > | Runway > (17/35) > > | > > | > > > > > > about three miles > > > > DOWNTOWN DALLAS TEXAS > > > > As for large metallic structures...there are two hangars built by Howard > > Hughes for something really big right on the 17/35 runway. Other than > that > > there is an FBI/U.S. Customs helicopter hangar (which tends to be rather a > > secretive place) on the South end of the field and a medium sized strip > mall > > just across a highway to the South. There is also a six story Wells Fargo > > Bank down by the FBI. > > > > There is a National Guard Armory on the West side of the field which, I > > believe has some radio antennae sticking up in the wooded area adjacent to > > it... I'll check on the way home. My wife (she's a pilot also) says she > > thinks the bank tower has dish antennae on it... either the bank or the > FBI. > > That's her side of the plane so I never look out there, because I don't > want > > to see what she's going to hit, and will check on it on way home. > > > > The antennas are well grounded, but are on the aft slope of the top of the > > fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF > > which required triaxial cable I changed EVERYTHING to triaxial as it just > > seemed the logical thing to do. > > > > They are too close together (about 2 feet apart), but are about 5 feet aft > > of the Loran antenna. The transponder is under the foward fuselage (blade > > type) and the ADF & marker beacon are on the bottom aft fuselage. The > > aftmost comm antenna is very close to the vertical stabilizer which has an > > ABS plastic shroud on the leading edge to affect airflow. I never thought > > much about the static from plastic as all I've read indicates that our > plane > > is too slow... we cruise at ~145-150 mph with take-off and climb at 90-100 > > mph. Should I install some static wicks? > > > > We only get this static garbage at this airport... no where else we have > > flown has given us any problems and we have been into some strange places > > like the Arizona & New Mexico desert and along the U.S./ Mexico border. > > > > You will never know how much you are helping... I tend to be a rather > > tenacious person and want very much to understand as much as possible > about > > what is going on and how to eliminate it... if possible. > > > > David > > > > > > ----- Original Message ----- > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > Hello again > > > > > > There can be a very considerable difference in resitance readings of a > VOM > > > for forward v. reverse polarity if you have an "Active Device" in the > > > circuit... i.e. a Diode, or a Transistor. Looking from the battery, > you > > > could be looking at several of these, (diodes or transistors) which are > > > used for noise suppression, voltage spike protection, even internally > in > > a > > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated by > a > > > circuit breaker. > > > > > > If there is No change as you indicated, that simply verifies that you > > likely > > > DO NOT have an Active Device in the Battery Bus Circuit, since Active > > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is > > typically > > > MUCH higher in one polarity than the other. > > > > > > If your VOM has a 1 amp direct reading capability, the way to proceed > is > > to > > > disconnected the + lead from the battery. Set your VOM to DC CURRENT > > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in SERIES > > > with the battery, i.e., VOM - lead to battery cable (where the LOAD is), > > and > > > + lead to the battery + lead (Current Source). > > > > > > The reading you will get will be in either MILLIAMPS (ma) or AMPS (A).. > > > depending on your meter...if the scale is calibrated in (ma), move the > > > decimal place to the right 3 spaces (X 1000) for (amps) > > > > > > If you are using your fully charged aircraft battery,. you should get > > 1.09 > > > Amps showing on the meter.: > > > > > > 12 VDC/11 OHMS = 1.09 AMPS. > > > > > > Note that if you use external power the voltage might be higher, up to > 14 > > > volts.. that might damage your VOM since that is 1.3 Amps. > > > > > > You may have done this already according to your note, but you read the > > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter > is > > > different, I have no way of knowing what the .245 you referred to really > > is. > > > > > > The nice thing about using a CURRENT METER is that you can leave it > hooked > > > up and go disconnect various things that power goes to, i.e voltage > > > regulators, bulkhead connectors, circuit breakers, etc. and with a quick > > > check see if the current dropped to ZERO.... BINGO... your problem is in > > > THAT CIRCUIT. > > > > > > As to your question about Avionics Signal and Power Grounds. NO, they > > MUST > > > be connected together at ONE and ONLY one place for noise immunity... > > also > > > helps with lighning protection. Signal ground is not the same as AUDIO > > > ground. > > > > > > That is not to say that Avionics Shops do things right... as you have > > found > > > out. > > > > > > There is one other thing I should tell you about. Audio Panels are an > > even > > > MORE complicated item. In Audio Panels, they may have as many as 2 MORE > > > types of Grounds. King (KMA-24) is famous for this. You have to Isolate > > the > > > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot > > audio > > > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND. > > > These suckers can be real bears, and the source of Noise PICKUP (from > > > external sources such as motors, sparks (like bad shielding on spark > plug > > > wires) and even external to the aircraft.. industrial sources. > > > > > > The Noise Zone you mention is intriguing. There are two ways of looking > > at > > > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2), > > that > > > there exists a SHIELD from radiation. > > > > > > I believe the first is what everybody has been focused on. However, the > > > second is just as likely if not more so. For example, if there is a > > > significant magnetic disturbance in the area, or a very large metalic > > > structure in the area, or a hill with a lot of iron content.. etc. etc. > > > these can shield the background RF Noise Level The Automatic Gain > > Control > > > (AGC) circuits in you radios, and/or audio panel, would compensate by > > > INCREASING the GAIN... that would result in audio STATIC...exactly like > > what > > > you get when listening to your AM radio in the car when you drive > through > > a > > > tunnel. > > > > > > I got the point you made that you had EVERYTHING disconnected except > the > > > Battery and the Avionics DC bus and of course the radios that power > them.. > > > One thing you should also do, is turn of your Transponder. Also, if the > > > Antenna Coax for the Transponder and the DME (if you have one) are run > > > parallel with other wiring bundles, that can be a source of severe > static. > > > I always use Double Shielded Coax for these devices... some Av Shops do > > > not... and if I have to cross a wire bundle, I do it at as close to 90 > > > degrees as I can.(the Electric and Magnetic Fields no not couple to the > > > other cable when; you do that) Obviously it pays to keep these Coax > > leads > > > as short as possible (but must generally be no shorter than 3 feet (1/2 > > wave > > > length). > > > > > > Another general practice to follow is good GROUND PLANES for the > antennas. > > > What that means generally, is as much flat metal around the antenna as > > your > > > airplane and avionics can afford; keep radiating elements like DME and > > > Transponder seperated by 6' from each other.. as well as from very low > > > signal sources like LORAN, GPS...Keep the Comm antenna away from those > as > > > well... and strangely enough, keep these well away and UP-STREAM > > > (airstream) from non-electrically conductive surfaces such as > Plexiglass, > > > Fiberglass etc. (these create static electricity that can couple the > > > discharge via inonizatiotion of the airstream) Then, have a Good Low > > ohmic > > > contact for the antennas. That means cleaning away all paint where the > > > antenna mounts, and Alodining the area. and on the INSIDE of the > > airplane, > > > make sure that your have a good clean contact in like fashion for the > > > antenna mounting nuts/bolts. > > > > > > I just received another e-mail from you... about the odd charging habits > > of > > > your airplane. Keep in mind, that a fully charged battery is 12 VDC. > > > However, your voltage regulator puts out between 13.5 and 14.00 volts > > > depending on the current draw, and the internal setting of you voltage > > > regulator. You would be surprised at the variation in "Idling Current" > > from > > > one Regulator to the next. So, it does NOT surprise me that even after > > > starting your engines with a full battery, that they do a little chargin > > for > > > a while. What DOES surprise me is the CYCLING you mentioned. That was > > > common in the old days of RELAY type voltage regulagtors, but NOT for > > Solid > > > state Alternator Regulators. > > > > > > Do you have some sort of switching arangement for left/right engine > > > alternators? > > > > > > Luc > > > > > > > > > ----- Original Message ----- > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > To: > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > Luc... > > > > > > > > The resistance didn't change with a reverse in polarity... it rarely > > does. > > > > > > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran a > > > check > > > > with the +/- cables I got .245 volt flow in either direction. > > > > > > > > You raise an interesting point about the two different types of > > grounds... > > > > power and audio. Both are separated in the wiring harness, but > > connected > > > to > > > > the same center point ground. Should there be two center point > grounds? > > > > > > > > Everything is very clean as I just rebuilt the wiring harness. I have > > had > > > > it out twice and rechecked for faulty wiring or shielding touching the > > > > center wire and it checks out just fine. > > > > > > > > With the DC power source hooked directly to the power cable (I come > off > > > the > > > > power bus with one power cable to the audio panel, 2 NavComs, > > transponder, > > > > ADF and intercom though another set of breakers) to the radio stack, > the > > > > only thing I eliminated was the battery and the associated wiring... > all > > > > other noise sources (motors, alternator, gyros, etc.) were always off. > > I > > > > was getting the hum just off the battery power with no other motors, > > > > solenoids, regulators, gyros or anything turned on even connected. > > > > > > > > The + cable was the one with the crimp in it. The negative cable is > > only > > > > about 18" long and connected to the frame. > > > > > > > > I have not checked the grounding strap from the engine to the firewall > > > > within the last two months, but will be checking that also along with > > the > > > > starter cables, ammeter cables (which I found had some "burned spots" > on > > > > them which was hidden from view until you "unbundled" all the wiring) > > and > > > > installing an AmeriKing DC filter and Alternator filter. I've always > > > though > > > > > > > > Last year I replaced all the antenna cables as I found them to be > > bundled > > > > and taped to the + power cable. I also replaced all the comm antennae > > > > (fiberglass and cracked) with stainless steel, which helped a lot. > The > > > > controlled field I fly out of has a "cone of static" which many > complain > > > > about, but the FAA and FCC can't seem to isolate or do anything about, > > but > > > > rather claim it's everybody's radios... when you lift off, sometimes, > > the > > > > static is so bad you have to turn off the radios... > > > > > > > > I also replaced the alternator, voltage regulator and OV regulator > plus > > > all > > > > the associated wiring as some Avionics moron had butt spliced the > field > > > wire > > > > "INSIDE" the firewall cannon plug. The butt splice was broken and, of > > > > course, the field wire was going to ground. After 3 avionics shops > > > checked > > > > my alternator I took it out myself and found 3 diodes were bad... > > > > AeroElectric found that one more was bad when they replaced my > > alternator > > > > with an upgraded version with larger bearings. > > > > > > > > Yesterday as I pulled out the + battery power cable, I found all the > > > lights, > > > > strobe, electric fuel pump, and fuel sensors taped (relatively new > > looking > > > > tape) to the + power cable. Needless to say, during it's 36 year > > > existence, > > > > maintenance has always been done in FAA certified shops and done with > a > > > very > > > > high level of poor quality. > > > > > > > > I honestly think this is a wiring problem relative to 36 y/o wire, but > I > > > > won't know until I get all the wiring replaced and according to Beech > > > wiring > > > > diagram specifications. > > > > > > > > Thanks for you help and input... > > > > > > > > David J. Spencer > > > > Super3 > > > > djs(at)54Transmission.com > > > > > > > > > > > > ----- Original Message ----- > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > To: > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > What was the reverse polarity reading? I assume since you did not > > give > > > a > > > > > value for another range on the VOM, that it was a Digitial Type. > > > > > > > > > > Do you have a 1 amp Current meter? From the ohmic check, that's > about > > > the > > > > > current you are drawing if this is a DC load. If not, hook a 100 > ohm > > > > > resistor in series with the + battery Cable and measure the voltage > > > drop > > > > > across the resistor. > > > > > > > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic > contact) > > > are > > > > > EVERYTHING. > > > > > > > > > > However, there are frequently 2 ground levels, SIGNAL ground and > POWER > > > > > ground. Great care must be taken when assembling your avionics to > > keep > > > > > these two seperate, and connect them only at a SINGLE POINT ground. > > > > > > > > > > It is not a bad idea to stick your head under the panel, and clean > the > > > > > single point avionics ground to make sure the spade lugs and washers > > > are > > > > > not oxidized (high ohmic contact) > > > > > > > > > > It does not surprise me that with EXTERNAL DC power, that you do > NOT > > > have > > > > > radio hum. since your do NOT have a source of noise.. > > > > generator/alternator, > > > > > motors, etc. > > > > > > > > > > You did not mention if it was the + or the - battery lead that had a > > > crimp > > > > > splice in it. If it was in the + lead. other than creating a > voltage > > > > > drop... which would be reflected to the voltage regulator, i.e. the > > > > > generator/alternator would be putting out more voltage than it > should > > > > > because it senses a Battery slightly low voltage condition. If on > > the > > > > > other hand it was on the - side. as far as the radios go, it would > be > > > > like > > > > > putting a resistance between the - battery terminal and Chasis > Ground. > > > > This > > > > > could conceiveably cause the noise floor to be raised...but not > likely > > > if > > > > > yourGenrator/Alternator grouind is good... By the way... have to > > > checked > > > > > that to make sure you have a good & clean grounding strap from the > > > engine > > > > to > > > > > the firewall ?? > > > > > > > > > > Luc > > > > > > > > > > > > > > > ssage ----- > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > To: > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > Luc... > > > > > > > > > > > > There was approximately 11 ohms between the + & - with the correct > > > > > polarity > > > > > > hook up on the VOM. > > > > > > > > > > > > I took out the battery cable yesterday and found a split in the > > > > insulation > > > > > > about 3/8" long which had been taped over. The cable itself had > > been > > > > > > "crimped" creating a bulge and part of the internal wiring was > > broken > > > at > > > > > > that point. > > > > > > > > > > > > As best I could tell this open area was not laying on the skin but > , > > > > > rather, > > > > > > pointing away from the skin as the cable lay on the belly of the > > > plane. > > > > > > > > > > > > This is being corrected with new wiring and proper attachments. > > > > > > > > > > > > I hooked the radios up to a DC power source i.e. they are isolated > > > from > > > > > > anything (except the antenna)... and the hum went away. > > > > > > > > > > > > David J. Spencer > > > > > > Super3 > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > ----- Original Message ----- > > > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > > > To: > > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > What resistance do you read between the battery cable and > ground. > > > Be > > > > > sure > > > > > > > to take the measurement with the leads swapped as well as > standard > > > > > > polarity, > > > > > > > i.e. red lead to + and black to -.. If you are NOT using a > > digital > > > > VOM, > > > > > > > then also take values in both polarities in more than one RANGE > on > > > the > > > > > VOM > > > > > > > (active devices - diodes /transistors - are non-linear.. give > you > > a > > > > good > > > > > > > clue if the value changes). You may have another noise > suppression > > > > diode > > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with > > > possibly > > > > a > > > > > > bad > > > > > > > capacitor in it. > > > > > > > > > > > > > > Let me know what you get. > > > > > > > > > > > > > > Luc Martini > > > > > > > ----- Original Message ----- > > > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > > > To: > > > > > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > > > > > > > > > Has anyone ever replaced the battery relay on their Beech > A23-24 > > > > Super > > > > > > > III? > > > > > > > > > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt > > > > Voltage > > > > > > > > suppressor (diode) to eliminate voltage spikes flushing > through > > > the > > > > > > > system. > > > > > > > > > > > > > > > > I am replacing the battery, ground and starter cables with > new > > > > cable > > > > > > (AC > > > > > > > > grade #0 wire for the 40 amp system) and am wondering if > anyone > > > has > > > > > put > > > > > > > in > > > > > > > > a > > > > > > > > new Aircraft grade battery relay from an aircraft supply > > (Spruce) > > > > > > source > > > > > > > > battery relay in place of ours. > > > > > > > > > > > > > > > > I can currently remove the battery, diode and battery rely > and > > > get > > > > > > > current > > > > > > > > continuity (VOM) through the system from the positive cable > to > > > the > > > > > > > > negative cable or any > > > > > > > > ground... everything is off... i.e switches, breaker etc. > This > > > is > > > > > what > > > > > > > > some > > > > > > > > people think is causing a "hum" in the radios. The "hum" is > > > > present > > > > > > with > > > > > > > > the engine off and running the radios off a fully charged > > > battery. > > > > . > > > > > > > > Additionally, using the AC voltage test setup on the VOM I > can > > > > detect > > > > > > > > current flow between the positive cable and ground... any > > ground. > > > > > > > > > > > > > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > > > > > articles > > > > > > > > point > > > > > > > > to RMI induced noise through the hull by poor shielding on > the > > DC > > > > > power > > > > > > > > lines. > > > > > > > > > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > > > > > > > > > All comments welcomed... > > > > > > > > > > > > > > > > David J. Spencer > > > > > > > > Super3 > > > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 15, 2003
Luc... As far as magnetic deviation, I'm not aware of anything on the maps (and I've flown here for 30+ years) which indicates anything abnormal. Are you saying that static wicks and control surface bonding straps will increase the effective range of the radios? I don't have any problem with the cost of the wicks if they have advantages... I was just under the impression that unless you used a mach number as airspeed they didn't matter... wrong again. Yes other people have bitched about the static in the area... one instructor says it is really irritating. I went by the airport last night and found that not only do we have the TV, radio, microwave towers 5 miles south, we have a AM/FM radio station right on the field. That's the stuff on my wife's side of the plane that I never look at. They have got 4 dish antennae, and some sort of vertical strip antenna (about 4-6 8' vertical strips per antenna and about three of these) on a 6 story building just off the airport property. In addition there is a fire station with it's radio system just off the perimeter and a cell phone tower about a 1/4 mile off the property. I don't know of any Ham operators in the area, but could probably find some. Again thanks for the help... David ----- Original Message ----- From: "Martini Luc J.R." <martini(at)foxinternet.net> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Glad to help out. > > I forgot to ask if there is a significant Magnetic Deviation in that area > (what do they show on the maps?).. that would indicate an iron concentration > in the ground that could be acting as an RF shield. The effective range of > signals like VOR would also be decreased in such an area. > > As for Static wicks.. they never hurt, but are not all that cheap. Static > discharge is more a function of humidity (altitude) than airspeed. There > are 2 > advantages to Static wicks in addition to possibly reducing radio noise !) > is reduces galvanic corrosion..2) if you get hit by lightning, the tuffs > disappear instead of a piece of your flight control surfaces. > A lot of people don't realize that a plasma is not just a current, but > actually moves mater. The example I like to point out are the points in an > old distributor... No doubt you have noticed, that one side it builds a > mountain, and the other side a pit. The mountain and the pit are always on > the same side of the points. Current flows from - to +. when you open the > points a plasma arc forms. The flow of electrons (which are pretty light > but there are a lot of them and traveling at near the speed of > light. However, at the moment you open the circuit, the total energy in the > system must be equal, and you just stopped E=MC squared going that away > (toward the possitive terminal) instantaneously, For things to equal out, > metal (mass) must flow in the opposite direction to equalize energy state > equation. Electrons are light, so it does not take many atoms of > metal going much slower in the opposite direction for things to equal out, > quenching the plasma. The result however is that the metal builds up over > time on the - side of the points.. and that metal obviously comes from the > + side. > > So, if your airplane is hit with lightning, the tuffs will vaporize... In > military airplanes, they also provide bonding straps between the fuselage > and the flight control surfaces, so that no arcing occurs in the bearing/ > bolts/pins that hold them on. > > For the radios, you might be surprised how much you gain is Effective Range > for your receivers.. you find you pick up VOR stations for example quite a > few miles further out than before you spent your money and time on reducing > noise sources. > > I take it that other people have bitched about the noise problem in your > local area. > > With the advent of Cellphones, the general noise level have increased > dramatically. That is because cellphones are a SWITCHED System. When ever > you switch something on and off , you create noise. Take again for example, > the old car distributor with points. If you create a PLASMA, you are > radiating Radio Frequencies (Usually AM) , and as everyone knows, you > splatter AM noise > content all over the dial . If you SWITCH an RF signal on and off, the > amount of Noise content you generate is directly proportional to the Rise > and Fall time of the pulse. The faster the switch things on and off, the > worse it gets. A Zero Rise and Fall time,,, which is of course impossible, > would splatter equal amplitude from DC to Infinity. (and such noise could > also be FM -harmonic content) So, in short, > cellphones suck for radio... They have been the bane of Broadcast TV for > example.. > > And, as you might have expected, if the Ambient Noise Level goes UP, your > radio AGC compensates by turning the Signal Gain DOWN to compensate... Not > nice! > > Do you by chance know any Ham Radio Operators in your area??? Those guys > would be your best bet for finding the Noise SOURCE in the neighborhood. > There is an instrument called a Field Strength Meter, which is nothing more > than a Directional Antenna hooked to a TUNED Circuit, hooked up to an AM > detector (diode) and that in turn to a sensitive meter movement. In short, > a radio of sorts. They can go around and see where the strongest signals > are coming from, and use their ham gear to see if the noise is strictly AM > or possibly FM as well, and how much bandwidth is affected. THEN you can go > to the guys causing the problem and threaten them with legal action if they > don't clean up their act and/or go to the FAA and FCC with evidence in hand > and bitch. > > Luc > > > ----- Original Message ----- > From: "David J. Spencer" <djs(at)54Transmission.com> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Wow... what a wealth of information... You will never know how much this > is > > helping and I really appreciate your input. > > > > First of all this is a single engine plane (1967 Beech Musketeer, 200 hp > > Lycoming with fuel injection, A23-24 or Super III), so I only have one > > alternator. Now to the cycling which I mentioned. The VR was a contact > > type which I replaced with a Zeftronic unit. The cycling continued. I > then > > replaced the OV regulator with the matched Zeftronic solid state affair > and > > the cycling has stopped. I thought it might be one or the other as > nothing > > except the alternator and intercom were running when I last got fed up > with > > the noise. > > > > Turn off the alternator and the noise went away. It just made sense and > the > > VR & OV were both original equipment and 36+ years old. > > > > Thank you... You are correct for correcting me about resistance with or > > without inline devices... I just wasn't thinking when I said there is no > > difference as I always try to simplify the circuit to it's barest > essentials > > and then load on devices until I find a problem. Just my untrained > > methodology. > > > > I will run the amperage test when I get some new battery cable installed. > I > > bought #4 as it met the continuous usage requirements as per the chart on > > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"... > HOWEVER, > > the plane came with #0 wire and I am going to replace it with #0 wire. > The > > run from the battery to the starter solenoid is about 12 feet (12 volt > > system) and then another 5 feet to the starter. The alternator is a 40 > amp > > unit, but my guess is that the amperage on engine start may be high enough > > to warrant the heavier cable. Anyway what the hell it's just money and it > > "might" prevent something I don't understand is going on... safe is better > > than crispy. > > > > Now to the audio panel. I have a Terra TMA 230 with a marker beacon and > two > > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio > stack. > > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics > > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has > three > > audio grounds (connected) and one chassis ground. > > > > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR > THE > > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I also > > have not put a ground on the radio trays themselves... I think I should. > > > > Also, my centerpoint system is a terminal block where all the posts are > > connected to the same frame point as the ground. This allowed me to > create > > a neat little area where all the grounds (except the ones I just > mentioned) > > are located. The intercom requires insulating all the headset jacks (with > > isolation washers) and using the centerpoint ground. > > > > Now to the Cone of Static... below is a diagram of the airport in > > relationship to some 1600' AGL radio, TV & Microwave transmission towers > > which are South of the field about 5 miles. The airport is directly > between > > the towers and Downtown Dallas Texas. Is it possible that the towers > could > > be transmitting a directional signal toward downtown? > > > > > > ++++ > > > > +++++ Radio Transmission towers (~15 @ 1600' AGL) > > > > +++++ > > > > > about > > five miles to towers > > > > > > | > > | > > | Runway > (17/35) > > | > > | > > > > > > about three miles > > > > DOWNTOWN DALLAS TEXAS > > > > As for large metallic structures...there are two hangars built by Howard > > Hughes for something really big right on the 17/35 runway. Other than > that > > there is an FBI/U.S. Customs helicopter hangar (which tends to be rather a > > secretive place) on the South end of the field and a medium sized strip > mall > > just across a highway to the South. There is also a six story Wells Fargo > > Bank down by the FBI. > > > > There is a National Guard Armory on the West side of the field which, I > > believe has some radio antennae sticking up in the wooded area adjacent to > > it... I'll check on the way home. My wife (she's a pilot also) says she > > thinks the bank tower has dish antennae on it... either the bank or the > FBI. > > That's her side of the plane so I never look out there, because I don't > want > > to see what she's going to hit, and will check on it on way home. > > > > The antennas are well grounded, but are on the aft slope of the top of the > > fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF > > which required triaxial cable I changed EVERYTHING to triaxial as it just > > seemed the logical thing to do. > > > > They are too close together (about 2 feet apart), but are about 5 feet aft > > of the Loran antenna. The transponder is under the foward fuselage (blade > > type) and the ADF & marker beacon are on the bottom aft fuselage. The > > aftmost comm antenna is very close to the vertical stabilizer which has an > > ABS plastic shroud on the leading edge to affect airflow. I never thought > > much about the static from plastic as all I've read indicates that our > plane > > is too slow... we cruise at ~145-150 mph with take-off and climb at 90-100 > > mph. Should I install some static wicks? > > > > We only get this static garbage at this airport... no where else we have > > flown has given us any problems and we have been into some strange places > > like the Arizona & New Mexico desert and along the U.S./ Mexico border. > > > > You will never know how much you are helping... I tend to be a rather > > tenacious person and want very much to understand as much as possible > about > > what is going on and how to eliminate it... if possible. > > > > David > > > > > > ----- Original Message ----- > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > Hello again > > > > > > There can be a very considerable difference in resitance readings of a > VOM > > > for forward v. reverse polarity if you have an "Active Device" in the > > > circuit... i.e. a Diode, or a Transistor. Looking from the battery, > you > > > could be looking at several of these, (diodes or transistors) which are > > > used for noise suppression, voltage spike protection, even internally > in > > a > > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated by > a > > > circuit breaker. > > > > > > If there is No change as you indicated, that simply verifies that you > > likely > > > DO NOT have an Active Device in the Battery Bus Circuit, since Active > > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is > > typically > > > MUCH higher in one polarity than the other. > > > > > > If your VOM has a 1 amp direct reading capability, the way to proceed > is > > to > > > disconnected the + lead from the battery. Set your VOM to DC CURRENT > > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in SERIES > > > with the battery, i.e., VOM - lead to battery cable (where the LOAD is), > > and > > > + lead to the battery + lead (Current Source). > > > > > > The reading you will get will be in either MILLIAMPS (ma) or AMPS (A).. > > > depending on your meter...if the scale is calibrated in (ma), move the > > > decimal place to the right 3 spaces (X 1000) for (amps) > > > > > > If you are using your fully charged aircraft battery,. you should get > > 1.09 > > > Amps showing on the meter.: > > > > > > 12 VDC/11 OHMS = 1.09 AMPS. > > > > > > Note that if you use external power the voltage might be higher, up to > 14 > > > volts.. that might damage your VOM since that is 1.3 Amps. > > > > > > You may have done this already according to your note, but you read the > > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter > is > > > different, I have no way of knowing what the .245 you referred to really > > is. > > > > > > The nice thing about using a CURRENT METER is that you can leave it > hooked > > > up and go disconnect various things that power goes to, i.e voltage > > > regulators, bulkhead connectors, circuit breakers, etc. and with a quick > > > check see if the current dropped to ZERO.... BINGO... your problem is in > > > THAT CIRCUIT. > > > > > > As to your question about Avionics Signal and Power Grounds. NO, they > > MUST > > > be connected together at ONE and ONLY one place for noise immunity... > > also > > > helps with lighning protection. Signal ground is not the same as AUDIO > > > ground. > > > > > > That is not to say that Avionics Shops do things right... as you have > > found > > > out. > > > > > > There is one other thing I should tell you about. Audio Panels are an > > even > > > MORE complicated item. In Audio Panels, they may have as many as 2 MORE > > > types of Grounds. King (KMA-24) is famous for this. You have to Isolate > > the > > > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot > > audio > > > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND. > > > These suckers can be real bears, and the source of Noise PICKUP (from > > > external sources such as motors, sparks (like bad shielding on spark > plug > > > wires) and even external to the aircraft.. industrial sources. > > > > > > The Noise Zone you mention is intriguing. There are two ways of looking > > at > > > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2), > > that > > > there exists a SHIELD from radiation. > > > > > > I believe the first is what everybody has been focused on. However, the > > > second is just as likely if not more so. For example, if there is a > > > significant magnetic disturbance in the area, or a very large metalic > > > structure in the area, or a hill with a lot of iron content.. etc. etc. > > > these can shield the background RF Noise Level The Automatic Gain > > Control > > > (AGC) circuits in you radios, and/or audio panel, would compensate by > > > INCREASING the GAIN... that would result in audio STATIC...exactly like > > what > > > you get when listening to your AM radio in the car when you drive > through > > a > > > tunnel. > > > > > > I got the point you made that you had EVERYTHING disconnected except > the > > > Battery and the Avionics DC bus and of course the radios that power > them.. > > > One thing you should also do, is turn of your Transponder. Also, if the > > > Antenna Coax for the Transponder and the DME (if you have one) are run > > > parallel with other wiring bundles, that can be a source of severe > static. > > > I always use Double Shielded Coax for these devices... some Av Shops do > > > not... and if I have to cross a wire bundle, I do it at as close to 90 > > > degrees as I can.(the Electric and Magnetic Fields no not couple to the > > > other cable when; you do that) Obviously it pays to keep these Coax > > leads > > > as short as possible (but must generally be no shorter than 3 feet (1/2 > > wave > > > length). > > > > > > Another general practice to follow is good GROUND PLANES for the > antennas. > > > What that means generally, is as much flat metal around the antenna as > > your > > > airplane and avionics can afford; keep radiating elements like DME and > > > Transponder seperated by 6' from each other.. as well as from very low > > > signal sources like LORAN, GPS...Keep the Comm antenna away from those > as > > > well... and strangely enough, keep these well away and UP-STREAM > > > (airstream) from non-electrically conductive surfaces such as > Plexiglass, > > > Fiberglass etc. (these create static electricity that can couple the > > > discharge via inonizatiotion of the airstream) Then, have a Good Low > > ohmic > > > contact for the antennas. That means cleaning away all paint where the > > > antenna mounts, and Alodining the area. and on the INSIDE of the > > airplane, > > > make sure that your have a good clean contact in like fashion for the > > > antenna mounting nuts/bolts. > > > > > > I just received another e-mail from you... about the odd charging habits > > of > > > your airplane. Keep in mind, that a fully charged battery is 12 VDC. > > > However, your voltage regulator puts out between 13.5 and 14.00 volts > > > depending on the current draw, and the internal setting of you voltage > > > regulator. You would be surprised at the variation in "Idling Current" > > from > > > one Regulator to the next. So, it does NOT surprise me that even after > > > starting your engines with a full battery, that they do a little chargin > > for > > > a while. What DOES surprise me is the CYCLING you mentioned. That was > > > common in the old days of RELAY type voltage regulagtors, but NOT for > > Solid > > > state Alternator Regulators. > > > > > > Do you have some sort of switching arangement for left/right engine > > > alternators? > > > > > > Luc > > > > > > > > > ----- Original Message ----- > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > To: > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > Luc... > > > > > > > > The resistance didn't change with a reverse in polarity... it rarely > > does. > > > > > > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran a > > > check > > > > with the +/- cables I got .245 volt flow in either direction. > > > > > > > > You raise an interesting point about the two different types of > > grounds... > > > > power and audio. Both are separated in the wiring harness, but > > connected > > > to > > > > the same center point ground. Should there be two center point > grounds? > > > > > > > > Everything is very clean as I just rebuilt the wiring harness. I have > > had > > > > it out twice and rechecked for faulty wiring or shielding touching the > > > > center wire and it checks out just fine. > > > > > > > > With the DC power source hooked directly to the power cable (I come > off > > > the > > > > power bus with one power cable to the audio panel, 2 NavComs, > > transponder, > > > > ADF and intercom though another set of breakers) to the radio stack, > the > > > > only thing I eliminated was the battery and the associated wiring... > all > > > > other noise sources (motors, alternator, gyros, etc.) were always off. > > I > > > > was getting the hum just off the battery power with no other motors, > > > > solenoids, regulators, gyros or anything turned on even connected. > > > > > > > > The + cable was the one with the crimp in it. The negative cable is > > only > > > > about 18" long and connected to the frame. > > > > > > > > I have not checked the grounding strap from the engine to the firewall > > > > within the last two months, but will be checking that also along with > > the > > > > starter cables, ammeter cables (which I found had some "burned spots" > on > > > > them which was hidden from view until you "unbundled" all the wiring) > > and > > > > installing an AmeriKing DC filter and Alternator filter. I've always > > > though > > > > > > > > Last year I replaced all the antenna cables as I found them to be > > bundled > > > > and taped to the + power cable. I also replaced all the comm antennae > > > > (fiberglass and cracked) with stainless steel, which helped a lot. > The > > > > controlled field I fly out of has a "cone of static" which many > complain > > > > about, but the FAA and FCC can't seem to isolate or do anything about, > > but > > > > rather claim it's everybody's radios... when you lift off, sometimes, > > the > > > > static is so bad you have to turn off the radios... > > > > > > > > I also replaced the alternator, voltage regulator and OV regulator > plus > > > all > > > > the associated wiring as some Avionics moron had butt spliced the > field > > > wire > > > > "INSIDE" the firewall cannon plug. The butt splice was broken and, of > > > > course, the field wire was going to ground. After 3 avionics shops > > > checked > > > > my alternator I took it out myself and found 3 diodes were bad... > > > > AeroElectric found that one more was bad when they replaced my > > alternator > > > > with an upgraded version with larger bearings. > > > > > > > > Yesterday as I pulled out the + battery power cable, I found all the > > > lights, > > > > strobe, electric fuel pump, and fuel sensors taped (relatively new > > looking > > > > tape) to the + power cable. Needless to say, during it's 36 year > > > existence, > > > > maintenance has always been done in FAA certified shops and done with > a > > > very > > > > high level of poor quality. > > > > > > > > I honestly think this is a wiring problem relative to 36 y/o wire, but > I > > > > won't know until I get all the wiring replaced and according to Beech > > > wiring > > > > diagram specifications. > > > > > > > > Thanks for you help and input... > > > > > > > > David J. Spencer > > > > Super3 > > > > djs(at)54Transmission.com > > > > > > > > > > > > ----- Original Message ----- > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > To: > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > What was the reverse polarity reading? I assume since you did not > > give > > > a > > > > > value for another range on the VOM, that it was a Digitial Type. > > > > > > > > > > Do you have a 1 amp Current meter? From the ohmic check, that's > about > > > the > > > > > current you are drawing if this is a DC load. If not, hook a 100 > ohm > > > > > resistor in series with the + battery Cable and measure the voltage > > > drop > > > > > across the resistor. > > > > > > > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic > contact) > > > are > > > > > EVERYTHING. > > > > > > > > > > However, there are frequently 2 ground levels, SIGNAL ground and > POWER > > > > > ground. Great care must be taken when assembling your avionics to > > keep > > > > > these two seperate, and connect them only at a SINGLE POINT ground. > > > > > > > > > > It is not a bad idea to stick your head under the panel, and clean > the > > > > > single point avionics ground to make sure the spade lugs and washers > > > are > > > > > not oxidized (high ohmic contact) > > > > > > > > > > It does not surprise me that with EXTERNAL DC power, that you do > NOT > > > have > > > > > radio hum. since your do NOT have a source of noise.. > > > > generator/alternator, > > > > > motors, etc. > > > > > > > > > > You did not mention if it was the + or the - battery lead that had a > > > crimp > > > > > splice in it. If it was in the + lead. other than creating a > voltage > > > > > drop... which would be reflected to the voltage regulator, i.e. the > > > > > generator/alternator would be putting out more voltage than it > should > > > > > because it senses a Battery slightly low voltage condition. If on > > the > > > > > other hand it was on the - side. as far as the radios go, it would > be > > > > like > > > > > putting a resistance between the - battery terminal and Chasis > Ground. > > > > This > > > > > could conceiveably cause the noise floor to be raised...but not > likely > > > if > > > > > yourGenrator/Alternator grouind is good... By the way... have to > > > checked > > > > > that to make sure you have a good & clean grounding strap from the > > > engine > > > > to > > > > > the firewall ?? > > > > > > > > > > Luc > > > > > > > > > > > > > > > ssage ----- > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > To: > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > Luc... > > > > > > > > > > > > There was approximately 11 ohms between the + & - with the correct > > > > > polarity > > > > > > hook up on the VOM. > > > > > > > > > > > > I took out the battery cable yesterday and found a split in the > > > > insulation > > > > > > about 3/8" long which had been taped over. The cable itself had > > been > > > > > > "crimped" creating a bulge and part of the internal wiring was > > broken > > > at > > > > > > that point. > > > > > > > > > > > > As best I could tell this open area was not laying on the skin but > , > > > > > rather, > > > > > > pointing away from the skin as the cable lay on the belly of the > > > plane. > > > > > > > > > > > > This is being corrected with new wiring and proper attachments. > > > > > > > > > > > > I hooked the radios up to a DC power source i.e. they are isolated > > > from > > > > > > anything (except the antenna)... and the hum went away. > > > > > > > > > > > > David J. Spencer > > > > > > Super3 > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > ----- Original Message ----- > > > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > > > To: > > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > What resistance do you read between the battery cable and > ground. > > > Be > > > > > sure > > > > > > > to take the measurement with the leads swapped as well as > standard > > > > > > polarity, > > > > > > > i.e. red lead to + and black to -.. If you are NOT using a > > digital > > > > VOM, > > > > > > > then also take values in both polarities in more than one RANGE > on > > > the > > > > > VOM > > > > > > > (active devices - diodes /transistors - are non-linear.. give > you > > a > > > > good > > > > > > > clue if the value changes). You may have another noise > suppression > > > > diode > > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with > > > possibly > > > > a > > > > > > bad > > > > > > > capacitor in it. > > > > > > > > > > > > > > Let me know what you get. > > > > > > > > > > > > > > Luc Martini > > > > > > > ----- Original Message ----- > > > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > > > To: > > > > > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > > > > > > > > > Has anyone ever replaced the battery relay on their Beech > A23-24 > > > > Super > > > > > > > III? > > > > > > > > > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a Kipvolt > > > > Voltage > > > > > > > > suppressor (diode) to eliminate voltage spikes flushing > through > > > the > > > > > > > system. > > > > > > > > > > > > > > > > I am replacing the battery, ground and starter cables with > new > > > > cable > > > > > > (AC > > > > > > > > grade #0 wire for the 40 amp system) and am wondering if > anyone > > > has > > > > > put > > > > > > > in > > > > > > > > a > > > > > > > > new Aircraft grade battery relay from an aircraft supply > > (Spruce) > > > > > > source > > > > > > > > battery relay in place of ours. > > > > > > > > > > > > > > > > I can currently remove the battery, diode and battery rely > and > > > get > > > > > > > current > > > > > > > > continuity (VOM) through the system from the positive cable > to > > > the > > > > > > > > negative cable or any > > > > > > > > ground... everything is off... i.e switches, breaker etc. > This > > > is > > > > > what > > > > > > > > some > > > > > > > > people think is causing a "hum" in the radios. The "hum" is > > > > present > > > > > > with > > > > > > > > the engine off and running the radios off a fully charged > > > battery. > > > > . > > > > > > > > Additionally, using the AC voltage test setup on the VOM I > can > > > > detect > > > > > > > > current flow between the positive cable and ground... any > > ground. > > > > > > > > > > > > > > > > > > > > > > > > I'm using certer point grounding, but all the avionics manual > > > > > articles > > > > > > > > point > > > > > > > > to RMI induced noise through the hull by poor shielding on > the > > DC > > > > > power > > > > > > > > lines. > > > > > > > > > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > > > > > > > > > All comments welcomed... > > > > > > > > > > > > > > > > David J. Spencer > > > > > > > > Super3 > > > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Battery Solenoid (Relay)
Date: Apr 15, 2003
Hi. The "Vertical Strips" sound like a Log-Periodic antenna...Your best bet is to get the assistance of a Ham Operator to ferit out the source of the noise The AM/FM station on the field might be a problem. If that is is transmission site, they could be spreading harmonic content (multiples of their carrier and sideband frequencies) at relatively high power levels in the general vicinity of the antenna. The Ott cable to the Starter is a good idea. But 15 feet is still a very long run. If ever you have to get another starter, go for one of the new "Rare Earth Metal Magnet" types. These not only are smaller and lighter, but they use significantly less current. The strong magnetic fields of the Rare Earth Magnets, tighter tolerances of the Rotor to Field gap, greatly reduce the losses in the motor, which in part are expressed as thermal loss i.e. they don't get nearly as hot or as quick as the old boat anchers. And,. less current draw means less line-loss in the power cable, means the faster cranking speed, and no burnt wires and longer starter life. The answer to your questions on static wicks and control surface bonding is YES, if you fly in a relatively dry climate, and/or like to get up there above the clouds, then static wicks can make a noticeable difference in radio noise reduction and with that increase the effective range of the radios. True, as you increase speed toward and above mach, the energy imparted to the air causes ionication, but if you rub your pussy (cat) across the plexiglass windshield (not recommended) you surely will also create static.... The example I like to point out, is Electric Power Transmission Lines. Many unfortunately uninformed linemen have been killed by static discharge on the lines. They thought they were safe because they knew that the power was off on the lines because they had pulled the circuit breakers;. but, a slight dry wind blowing over miles of wire, creates unbelieveably high static voltages with a very high peak current capability. The wires act like the plates of a very large capacitor to ground.... ZAP! Luc ----- Original Message ----- From: "David J. Spencer" <djs(at)54Transmission.com> Subject: Re: Avionics-List: Battery Solenoid (Relay) > > Luc... > > As far as magnetic deviation, I'm not aware of anything on the maps (and > I've flown here for 30+ years) which indicates anything abnormal. > > Are you saying that static wicks and control surface bonding straps will > increase the effective range of the radios? I don't have any problem with > the cost of the wicks if they have advantages... I was just under the > impression that unless you used a mach number as airspeed they didn't > matter... wrong again. > > Yes other people have bitched about the static in the area... one instructor > says it is really irritating. > > I went by the airport last night and found that not only do we have the TV, > radio, microwave towers 5 miles south, we have a AM/FM radio station right > on the field. That's the stuff on my wife's side of the plane that I never > look at. They have got 4 dish antennae, and some sort of vertical strip > antenna (about 4-6 8' vertical strips per antenna and about three of > these) on a 6 story building just off the airport property. > > In addition there is a fire station with it's radio system just off the > perimeter and a cell phone tower about a 1/4 mile off the property. > > I don't know of any Ham operators in the area, but could probably find some. > > Again thanks for the help... > > David > > > ----- Original Message ----- > From: "Martini Luc J.R." <martini(at)foxinternet.net> > To: > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > Glad to help out. > > > > I forgot to ask if there is a significant Magnetic Deviation in that area > > (what do they show on the maps?).. that would indicate an iron > concentration > > in the ground that could be acting as an RF shield. The effective range > of > > signals like VOR would also be decreased in such an area. > > > > As for Static wicks.. they never hurt, but are not all that cheap. Static > > discharge is more a function of humidity (altitude) than airspeed. There > > are 2 > > advantages to Static wicks in addition to possibly reducing radio noise !) > > is reduces galvanic corrosion..2) if you get hit by lightning, the tuffs > > disappear instead of a piece of your flight control surfaces. > > A lot of people don't realize that a plasma is not just a current, but > > actually moves mater. The example I like to point out are the points in > an > > old distributor... No doubt you have noticed, that one side it builds a > > mountain, and the other side a pit. The mountain and the pit are always > on > > the same side of the points. Current flows from - to +. when you open > the > > points a plasma arc forms. The flow of electrons (which are pretty light > > but there are a lot of them and traveling at near the speed of > > light. However, at the moment you open the circuit, the total energy in > the > > system must be equal, and you just stopped E=MC squared going that away > > (toward the possitive terminal) instantaneously, For things to equal out, > > metal (mass) must flow in the opposite direction to equalize energy state > > equation. Electrons are light, so it does not take many atoms of > > metal going much slower in the opposite direction for things to equal out, > > quenching the plasma. The result however is that the metal builds up over > > time on the - side of the points.. and that metal obviously comes from the > > + side. > > > > So, if your airplane is hit with lightning, the tuffs will vaporize... In > > military airplanes, they also provide bonding straps between the fuselage > > and the flight control surfaces, so that no arcing occurs in the bearing/ > > bolts/pins that hold them on. > > > > For the radios, you might be surprised how much you gain is Effective > Range > > for your receivers.. you find you pick up VOR stations for example quite > a > > few miles further out than before you spent your money and time on > reducing > > noise sources. > > > > I take it that other people have bitched about the noise problem in your > > local area. > > > > With the advent of Cellphones, the general noise level have increased > > dramatically. That is because cellphones are a SWITCHED System. When > ever > > you switch something on and off , you create noise. Take again for > example, > > the old car distributor with points. If you create a PLASMA, you are > > radiating Radio Frequencies (Usually AM) , and as everyone knows, you > > splatter AM noise > > content all over the dial . If you SWITCH an RF signal on and off, the > > amount of Noise content you generate is directly proportional to the Rise > > and Fall time of the pulse. The faster the switch things on and off, the > > worse it gets. A Zero Rise and Fall time,,, which is of course > impossible, > > would splatter equal amplitude from DC to Infinity. (and such noise could > > also be FM -harmonic content) So, in short, > > cellphones suck for radio... They have been the bane of Broadcast TV for > > example.. > > > > And, as you might have expected, if the Ambient Noise Level goes UP, your > > radio AGC compensates by turning the Signal Gain DOWN to compensate... Not > > nice! > > > > Do you by chance know any Ham Radio Operators in your area??? Those guys > > would be your best bet for finding the Noise SOURCE in the neighborhood. > > There is an instrument called a Field Strength Meter, which is nothing > more > > than a Directional Antenna hooked to a TUNED Circuit, hooked up to an AM > > detector (diode) and that in turn to a sensitive meter movement. In > short, > > a radio of sorts. They can go around and see where the strongest signals > > are coming from, and use their ham gear to see if the noise is strictly AM > > or possibly FM as well, and how much bandwidth is affected. THEN you can > go > > to the guys causing the problem and threaten them with legal action if > they > > don't clean up their act and/or go to the FAA and FCC with evidence in > hand > > and bitch. > > > > Luc > > > > > > ----- Original Message ----- > > From: "David J. Spencer" <djs(at)54Transmission.com> > > To: > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > Wow... what a wealth of information... You will never know how much > this > > is > > > helping and I really appreciate your input. > > > > > > First of all this is a single engine plane (1967 Beech Musketeer, 200 hp > > > Lycoming with fuel injection, A23-24 or Super III), so I only have one > > > alternator. Now to the cycling which I mentioned. The VR was a contact > > > type which I replaced with a Zeftronic unit. The cycling continued. I > > then > > > replaced the OV regulator with the matched Zeftronic solid state affair > > and > > > the cycling has stopped. I thought it might be one or the other as > > nothing > > > except the alternator and intercom were running when I last got fed up > > with > > > the noise. > > > > > > Turn off the alternator and the noise went away. It just made sense and > > the > > > VR & OV were both original equipment and 36+ years old. > > > > > > Thank you... You are correct for correcting me about resistance with or > > > without inline devices... I just wasn't thinking when I said there is no > > > difference as I always try to simplify the circuit to it's barest > > essentials > > > and then load on devices until I find a problem. Just my untrained > > > methodology. > > > > > > I will run the amperage test when I get some new battery cable > installed. > > I > > > bought #4 as it met the continuous usage requirements as per the chart > on > > > page 1-10 of Robert G. Horan's "Avionics Installation Handbook"... > > HOWEVER, > > > the plane came with #0 wire and I am going to replace it with #0 wire. > > The > > > run from the battery to the starter solenoid is about 12 feet (12 volt > > > system) and then another 5 feet to the starter. The alternator is a 40 > > amp > > > unit, but my guess is that the amperage on engine start may be high > enough > > > to warrant the heavier cable. Anyway what the hell it's just money and > it > > > "might" prevent something I don't understand is going on... safe is > better > > > than crispy. > > > > > > Now to the audio panel. I have a Terra TMA 230 with a marker beacon and > > two > > > Terra TXN-960 NavComs with glide slopes and ILS which I call a radio > > stack. > > > I also have a KLN-88, cooling fan, King KT-76 transponder, Sigtronics > > > SPA-400 intercom and Collins RCR-650/IND 650 ADF. The audio panel has > > three > > > audio grounds (connected) and one chassis ground. > > > > > > AND THANK YOU VERY MUCH -- YOU JUST JOGGED MY MEMORY-- THE GROUNDS FOR > > THE > > > ADF, TRANSPONDER & COOLING FAN ARE NOT ON THE CENTERPOINT SYSTEM. I > also > > > have not put a ground on the radio trays themselves... I think I should. > > > > > > Also, my centerpoint system is a terminal block where all the posts are > > > connected to the same frame point as the ground. This allowed me to > > create > > > a neat little area where all the grounds (except the ones I just > > mentioned) > > > are located. The intercom requires insulating all the headset jacks > (with > > > isolation washers) and using the centerpoint ground. > > > > > > Now to the Cone of Static... below is a diagram of the airport in > > > relationship to some 1600' AGL radio, TV & Microwave transmission towers > > > which are South of the field about 5 miles. The airport is directly > > between > > > the towers and Downtown Dallas Texas. Is it possible that the towers > > could > > > be transmitting a directional signal toward downtown? > > > > > > > > > ++++ > > > > > > +++++ Radio Transmission towers (~15 @ 1600' AGL) > > > > > > +++++ > > > > > > > > about > > > five miles to towers > > > > > > > > > | > > > | > > > | Runway > > (17/35) > > > | > > > | > > > > > > > > > about three miles > > > > > > DOWNTOWN DALLAS TEXAS > > > > > > As for large metallic structures...there are two hangars built by Howard > > > Hughes for something really big right on the 17/35 runway. Other than > > that > > > there is an FBI/U.S. Customs helicopter hangar (which tends to be rather > a > > > secretive place) on the South end of the field and a medium sized strip > > mall > > > just across a highway to the South. There is also a six story Wells > Fargo > > > Bank down by the FBI. > > > > > > There is a National Guard Armory on the West side of the field which, I > > > believe has some radio antennae sticking up in the wooded area adjacent > to > > > it... I'll check on the way home. My wife (she's a pilot also) says > she > > > thinks the bank tower has dish antennae on it... either the bank or the > > FBI. > > > That's her side of the plane so I never look out there, because I don't > > want > > > to see what she's going to hit, and will check on it on way home. > > > > > > The antennas are well grounded, but are on the aft slope of the top of > the > > > fuselage (fuselage much like a V-35 Bonanza). After putting in the ADF > > > which required triaxial cable I changed EVERYTHING to triaxial as it > just > > > seemed the logical thing to do. > > > > > > They are too close together (about 2 feet apart), but are about 5 feet > aft > > > of the Loran antenna. The transponder is under the foward fuselage > (blade > > > type) and the ADF & marker beacon are on the bottom aft fuselage. The > > > aftmost comm antenna is very close to the vertical stabilizer which has > an > > > ABS plastic shroud on the leading edge to affect airflow. I never > thought > > > much about the static from plastic as all I've read indicates that our > > plane > > > is too slow... we cruise at ~145-150 mph with take-off and climb at > 90-100 > > > mph. Should I install some static wicks? > > > > > > We only get this static garbage at this airport... no where else we have > > > flown has given us any problems and we have been into some strange > places > > > like the Arizona & New Mexico desert and along the U.S./ Mexico border. > > > > > > You will never know how much you are helping... I tend to be a rather > > > tenacious person and want very much to understand as much as possible > > about > > > what is going on and how to eliminate it... if possible. > > > > > > David > > > > > > > > > ----- Original Message ----- > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > To: > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > Hello again > > > > > > > > There can be a very considerable difference in resitance readings of a > > VOM > > > > for forward v. reverse polarity if you have an "Active Device" in the > > > > circuit... i.e. a Diode, or a Transistor. Looking from the battery, > > you > > > > could be looking at several of these, (diodes or transistors) which > are > > > > used for noise suppression, voltage spike protection, even > internally > > in > > > a > > > > voltage regulator, and on the BATTERY BUS CIRCUIT, i.e, not isolated > by > > a > > > > circuit breaker. > > > > > > > > If there is No change as you indicated, that simply verifies that you > > > likely > > > > DO NOT have an Active Device in the Battery Bus Circuit, since Active > > > > Devices are very NON LINEAR, i.e., the reading you get on a VOM is > > > typically > > > > MUCH higher in one polarity than the other. > > > > > > > > If your VOM has a 1 amp direct reading capability, the way to proceed > > is > > > to > > > > disconnected the + lead from the battery. Set your VOM to DC CURRENT > > > > (milliaps or amps) & to the 1 Amp RANGE. Then Connect the VOM in > SERIES > > > > with the battery, i.e., VOM - lead to battery cable (where the LOAD > is), > > > and > > > > + lead to the battery + lead (Current Source). > > > > > > > > The reading you will get will be in either MILLIAMPS (ma) or AMPS > (A).. > > > > depending on your meter...if the scale is calibrated in (ma), move > the > > > > decimal place to the right 3 spaces (X 1000) for (amps) > > > > > > > > If you are using your fully charged aircraft battery,. you should get > > > 1.09 > > > > Amps showing on the meter.: > > > > > > > > 12 VDC/11 OHMS = 1.09 AMPS. > > > > > > > > Note that if you use external power the voltage might be higher, up > to > > 14 > > > > volts.. that might damage your VOM since that is 1.3 Amps. > > > > > > > > You may have done this already according to your note, but you read > the > > > > VOLTS RANGE, rather than the AMPS RANGE on the dial. Since each meter > > is > > > > different, I have no way of knowing what the .245 you referred to > really > > > is. > > > > > > > > The nice thing about using a CURRENT METER is that you can leave it > > hooked > > > > up and go disconnect various things that power goes to, i.e voltage > > > > regulators, bulkhead connectors, circuit breakers, etc. and with a > quick > > > > check see if the current dropped to ZERO.... BINGO... your problem is > in > > > > THAT CIRCUIT. > > > > > > > > As to your question about Avionics Signal and Power Grounds. NO, they > > > MUST > > > > be connected together at ONE and ONLY one place for noise immunity... > > > also > > > > helps with lighning protection. Signal ground is not the same as > AUDIO > > > > ground. > > > > > > > > That is not to say that Avionics Shops do things right... as you have > > > found > > > > out. > > > > > > > > There is one other thing I should tell you about. Audio Panels are an > > > even > > > > MORE complicated item. In Audio Panels, they may have as many as 2 > MORE > > > > types of Grounds. King (KMA-24) is famous for this. You have to > Isolate > > > the > > > > AUDIO GROUNDS as well. and may have to isolate the Pilot and Co-pilot > > > audio > > > > from ANY OTHER audio ground, as well as isolation from CHASIS GROUND. > > > > These suckers can be real bears, and the source of Noise PICKUP (from > > > > external sources such as motors, sparks (like bad shielding on spark > > plug > > > > wires) and even external to the aircraft.. industrial sources. > > > > > > > > The Noise Zone you mention is intriguing. There are two ways of > looking > > > at > > > > the problem.. 1) that there exists a NOISE SOURCE in that area, or 2), > > > that > > > > there exists a SHIELD from radiation. > > > > > > > > I believe the first is what everybody has been focused on. However, > the > > > > second is just as likely if not more so. For example, if there is a > > > > significant magnetic disturbance in the area, or a very large metalic > > > > structure in the area, or a hill with a lot of iron content.. etc. > etc. > > > > these can shield the background RF Noise Level The Automatic Gain > > > Control > > > > (AGC) circuits in you radios, and/or audio panel, would compensate by > > > > INCREASING the GAIN... that would result in audio STATIC...exactly > like > > > what > > > > you get when listening to your AM radio in the car when you drive > > through > > > a > > > > tunnel. > > > > > > > > I got the point you made that you had EVERYTHING disconnected except > > the > > > > Battery and the Avionics DC bus and of course the radios that power > > them.. > > > > One thing you should also do, is turn of your Transponder. Also, if > the > > > > Antenna Coax for the Transponder and the DME (if you have one) are > run > > > > parallel with other wiring bundles, that can be a source of severe > > static. > > > > I always use Double Shielded Coax for these devices... some Av Shops > do > > > > not... and if I have to cross a wire bundle, I do it at as close to 90 > > > > degrees as I can.(the Electric and Magnetic Fields no not couple to > the > > > > other cable when; you do that) Obviously it pays to keep these Coax > > > leads > > > > as short as possible (but must generally be no shorter than 3 feet > (1/2 > > > wave > > > > length). > > > > > > > > Another general practice to follow is good GROUND PLANES for the > > antennas. > > > > What that means generally, is as much flat metal around the antenna as > > > your > > > > airplane and avionics can afford; keep radiating elements like DME > and > > > > Transponder seperated by 6' from each other.. as well as from very low > > > > signal sources like LORAN, GPS...Keep the Comm antenna away from those > > as > > > > well... and strangely enough, keep these well away and UP-STREAM > > > > (airstream) from non-electrically conductive surfaces such as > > Plexiglass, > > > > Fiberglass etc. (these create static electricity that can couple the > > > > discharge via inonizatiotion of the airstream) Then, have a Good Low > > > ohmic > > > > contact for the antennas. That means cleaning away all paint where > the > > > > antenna mounts, and Alodining the area. and on the INSIDE of the > > > airplane, > > > > make sure that your have a good clean contact in like fashion for the > > > > antenna mounting nuts/bolts. > > > > > > > > I just received another e-mail from you... about the odd charging > habits > > > of > > > > your airplane. Keep in mind, that a fully charged battery is 12 VDC. > > > > However, your voltage regulator puts out between 13.5 and 14.00 volts > > > > depending on the current draw, and the internal setting of you voltage > > > > regulator. You would be surprised at the variation in "Idling Current" > > > from > > > > one Regulator to the next. So, it does NOT surprise me that even > after > > > > starting your engines with a full battery, that they do a little > chargin > > > for > > > > a while. What DOES surprise me is the CYCLING you mentioned. That > was > > > > common in the old days of RELAY type voltage regulagtors, but NOT for > > > Solid > > > > state Alternator Regulators. > > > > > > > > Do you have some sort of switching arangement for left/right engine > > > > alternators? > > > > > > > > Luc > > > > > > > > > > > > ----- Original Message ----- > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > To: > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > Luc... > > > > > > > > > > The resistance didn't change with a reverse in polarity... it rarely > > > does. > > > > > > > > > > My VOM has a 1 amp capability. When I set it to AC voltage and ran > a > > > > check > > > > > with the +/- cables I got .245 volt flow in either direction. > > > > > > > > > > You raise an interesting point about the two different types of > > > grounds... > > > > > power and audio. Both are separated in the wiring harness, but > > > connected > > > > to > > > > > the same center point ground. Should there be two center point > > grounds? > > > > > > > > > > Everything is very clean as I just rebuilt the wiring harness. I > have > > > had > > > > > it out twice and rechecked for faulty wiring or shielding touching > the > > > > > center wire and it checks out just fine. > > > > > > > > > > With the DC power source hooked directly to the power cable (I come > > off > > > > the > > > > > power bus with one power cable to the audio panel, 2 NavComs, > > > transponder, > > > > > ADF and intercom though another set of breakers) to the radio stack, > > the > > > > > only thing I eliminated was the battery and the associated wiring... > > all > > > > > other noise sources (motors, alternator, gyros, etc.) were always > off. > > > I > > > > > was getting the hum just off the battery power with no other motors, > > > > > solenoids, regulators, gyros or anything turned on even connected. > > > > > > > > > > The + cable was the one with the crimp in it. The negative cable is > > > only > > > > > about 18" long and connected to the frame. > > > > > > > > > > I have not checked the grounding strap from the engine to the > firewall > > > > > within the last two months, but will be checking that also along > with > > > the > > > > > starter cables, ammeter cables (which I found had some "burned > spots" > > on > > > > > them which was hidden from view until you "unbundled" all the > wiring) > > > and > > > > > installing an AmeriKing DC filter and Alternator filter. I've > always > > > > though > > > > > > > > > > Last year I replaced all the antenna cables as I found them to be > > > bundled > > > > > and taped to the + power cable. I also replaced all the comm > antennae > > > > > (fiberglass and cracked) with stainless steel, which helped a lot. > > The > > > > > controlled field I fly out of has a "cone of static" which many > > complain > > > > > about, but the FAA and FCC can't seem to isolate or do anything > about, > > > but > > > > > rather claim it's everybody's radios... when you lift off, > sometimes, > > > the > > > > > static is so bad you have to turn off the radios... > > > > > > > > > > I also replaced the alternator, voltage regulator and OV regulator > > plus > > > > all > > > > > the associated wiring as some Avionics moron had butt spliced the > > field > > > > wire > > > > > "INSIDE" the firewall cannon plug. The butt splice was broken and, > of > > > > > course, the field wire was going to ground. After 3 avionics shops > > > > checked > > > > > my alternator I took it out myself and found 3 diodes were bad... > > > > > AeroElectric found that one more was bad when they replaced my > > > alternator > > > > > with an upgraded version with larger bearings. > > > > > > > > > > Yesterday as I pulled out the + battery power cable, I found all the > > > > lights, > > > > > strobe, electric fuel pump, and fuel sensors taped (relatively new > > > looking > > > > > tape) to the + power cable. Needless to say, during it's 36 year > > > > existence, > > > > > maintenance has always been done in FAA certified shops and done > with > > a > > > > very > > > > > high level of poor quality. > > > > > > > > > > I honestly think this is a wiring problem relative to 36 y/o wire, > but > > I > > > > > won't know until I get all the wiring replaced and according to > Beech > > > > wiring > > > > > diagram specifications. > > > > > > > > > > Thanks for you help and input... > > > > > > > > > > David J. Spencer > > > > > Super3 > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > > To: > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > What was the reverse polarity reading? I assume since you did > not > > > give > > > > a > > > > > > value for another range on the VOM, that it was a Digitial Type. > > > > > > > > > > > > Do you have a 1 amp Current meter? From the ohmic check, that's > > about > > > > the > > > > > > current you are drawing if this is a DC load. If not, hook a 100 > > ohm > > > > > > resistor in series with the + battery Cable and measure the > voltage > > > > drop > > > > > > across the resistor. > > > > > > > > > > > > As far as Radio noise in general GOOD GROUNDS (very low ohmic > > contact) > > > > are > > > > > > EVERYTHING. > > > > > > > > > > > > However, there are frequently 2 ground levels, SIGNAL ground and > > POWER > > > > > > ground. Great care must be taken when assembling your avionics > to > > > keep > > > > > > these two seperate, and connect them only at a SINGLE POINT > ground. > > > > > > > > > > > > It is not a bad idea to stick your head under the panel, and clean > > the > > > > > > single point avionics ground to make sure the spade lugs and > washers > > > > are > > > > > > not oxidized (high ohmic contact) > > > > > > > > > > > > It does not surprise me that with EXTERNAL DC power, that you do > > NOT > > > > have > > > > > > radio hum. since your do NOT have a source of noise.. > > > > > generator/alternator, > > > > > > motors, etc. > > > > > > > > > > > > You did not mention if it was the + or the - battery lead that had > a > > > > crimp > > > > > > splice in it. If it was in the + lead. other than creating a > > voltage > > > > > > drop... which would be reflected to the voltage regulator, i.e. > the > > > > > > generator/alternator would be putting out more voltage than it > > should > > > > > > because it senses a Battery slightly low voltage condition. If > on > > > the > > > > > > other hand it was on the - side. as far as the radios go, it > would > > be > > > > > like > > > > > > putting a resistance between the - battery terminal and Chasis > > Ground. > > > > > This > > > > > > could conceiveably cause the noise floor to be raised...but not > > likely > > > > if > > > > > > yourGenrator/Alternator grouind is good... By the way... have to > > > > checked > > > > > > that to make sure you have a good & clean grounding strap from the > > > > engine > > > > > to > > > > > > the firewall ?? > > > > > > > > > > > > Luc > > > > > > > > > > > > > > > > > > ssage ----- > > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > > To: > > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Luc... > > > > > > > > > > > > > > There was approximately 11 ohms between the + & - with the > correct > > > > > > polarity > > > > > > > hook up on the VOM. > > > > > > > > > > > > > > I took out the battery cable yesterday and found a split in the > > > > > insulation > > > > > > > about 3/8" long which had been taped over. The cable itself had > > > been > > > > > > > "crimped" creating a bulge and part of the internal wiring was > > > broken > > > > at > > > > > > > that point. > > > > > > > > > > > > > > As best I could tell this open area was not laying on the skin > but > > , > > > > > > rather, > > > > > > > pointing away from the skin as the cable lay on the belly of the > > > > plane. > > > > > > > > > > > > > > This is being corrected with new wiring and proper attachments. > > > > > > > > > > > > > > I hooked the radios up to a DC power source i.e. they are > isolated > > > > from > > > > > > > anything (except the antenna)... and the hum went away. > > > > > > > > > > > > > > David J. Spencer > > > > > > > Super3 > > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > From: "Martini Luc J.R." <martini(at)foxinternet.net> > > > > > > > To: > > > > > > > Subject: Re: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > What resistance do you read between the battery cable and > > ground. > > > > Be > > > > > > sure > > > > > > > > to take the measurement with the leads swapped as well as > > standard > > > > > > > polarity, > > > > > > > > i.e. red lead to + and black to -.. If you are NOT using a > > > digital > > > > > VOM, > > > > > > > > then also take values in both polarities in more than one > RANGE > > on > > > > the > > > > > > VOM > > > > > > > > (active devices - diodes /transistors - are non-linear.. give > > you > > > a > > > > > good > > > > > > > > clue if the value changes). You may have another noise > > suppression > > > > > diode > > > > > > > > somewhere, and/or an RC type (Band Pass) noise filter , with > > > > possibly > > > > > a > > > > > > > bad > > > > > > > > capacitor in it. > > > > > > > > > > > > > > > > Let me know what you get. > > > > > > > > > > > > > > > > Luc Martini > > > > > > > > ----- Original Message ----- > > > > > > > > From: "David J. Spencer" <djs(at)54Transmission.com> > > > > > > > > To: > > > > > > > > Subject: Avionics-List: Battery Solenoid (Relay) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi all... > > > > > > > > > > > > > > > > > > Has anyone ever replaced the battery relay on their Beech > > A23-24 > > > > > Super > > > > > > > > III? > > > > > > > > > > > > > > > > > > My relay seems to work fine, but is 36 y/o and uses a > Kipvolt > > > > > Voltage > > > > > > > > > suppressor (diode) to eliminate voltage spikes flushing > > through > > > > the > > > > > > > > system. > > > > > > > > > > > > > > > > > > I am replacing the battery, ground and starter cables with > > new > > > > > cable > > > > > > > (AC > > > > > > > > > grade #0 wire for the 40 amp system) and am wondering if > > anyone > > > > has > > > > > > put > > > > > > > > in > > > > > > > > > a > > > > > > > > > new Aircraft grade battery relay from an aircraft supply > > > (Spruce) > > > > > > > source > > > > > > > > > battery relay in place of ours. > > > > > > > > > > > > > > > > > > I can currently remove the battery, diode and battery rely > > and > > > > get > > > > > > > > current > > > > > > > > > continuity (VOM) through the system from the positive > cable > > to > > > > the > > > > > > > > > negative cable or any > > > > > > > > > ground... everything is off... i.e switches, breaker etc. > > This > > > > is > > > > > > what > > > > > > > > > some > > > > > > > > > people think is causing a "hum" in the radios. The "hum" > is > > > > > present > > > > > > > with > > > > > > > > > the engine off and running the radios off a fully charged > > > > battery. > > > > > . > > > > > > > > > Additionally, using the AC voltage test setup on the VOM I > > can > > > > > detect > > > > > > > > > current flow between the positive cable and ground... any > > > ground. > > > > > > > > > > > > > > > > > > > > > > > > > > > I'm using certer point grounding, but all the avionics > manual > > > > > > articles > > > > > > > > > point > > > > > > > > > to RMI induced noise through the hull by poor shielding on > > the > > > DC > > > > > > power > > > > > > > > > lines. > > > > > > > > > > > > > > > > > > Beech doesn't seem to have these parts anymore. > > > > > > > > > > > > > > > > > > All comments welcomed... > > > > > > > > > > > > > > > > > > David J. Spencer > > > > > > > > > Super3 > > > > > > > > > djs(at)54Transmission.com > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________________________________________________________
Date: Apr 26, 2003
From: Philip Rice <ricephil(at)pld.com>
Subject: Davtron & Narco
I need to install Davtron 701A digital ADF indicator to Narco ADF-31A I unable to find a maintenance manual for ADF-31A . I need to know where to located TP114 and TP116 Any help you can give me will be appreciate. Thank You Phil Rice ________________________________________________________________________________
Date: Apr 26, 2003
From: Michael Di Marco <mgdimarco(at)yahoo.com>
Subject: New Microline Installation
I just installed a Microline comm and xpndr. The comm is working great, but the xpndr is not always replying. ATC shows a strong return and accurate encoder when it does reply, but results are intermitent. Ideas? Mike Di Marco --------------------------------- ________________________________________________________________________________
From: KarkelB(at)aol.com
Date: Apr 26, 2003
Subject: Re:Davtron M903
Hi Folks, just wanted to know whether one can use the davtron digital vor to run a standard vor indicator. regards Karkel ________________________________________________________________________________
From: "Dave Ford" <dford(at)michweb.net>
Subject: wiring question
Date: Apr 26, 2003
I have the AK-350 encoder, an IK2000 engine monitor w/density altitude readout (requiring gray code input, looping out to another device), Garmin GTX327, Garmin GNC300XL. The transponder has a gray code input and 2 RS232 inputs to receive Icarus or Shadin type altitude info. It also has altitude output in Icarus format. The GPS has RS232 inputs to receive (I believe) Icarus or Shadin type info (according to installation manual). It also has a 232 output channel showing aviation type info (serial position, velocity, and navigation data) which I'm not sure where that info is to be used. I am currently thinking that from the encoder to the IK2000 with gray code looping that out to the transponder with a RS232 output going to the GPS unit with altitude info. Does that sound right? Next for the Navaid A/P does it get steering info from the GPS RS232 output NMEA format or from the GPS left/right steering info that would normally go to a Nav Indicator? Do I need the Smart Coupler with this unit? Dave Ford RV6 ________________________________________________________________________________
From: "Dave Ford" <dford(at)michweb.net>
Subject: Garmin info
Date: Apr 27, 2003
I just need to know know if the Garmin GTX327 transponder talks to the Garmin GPS GNC300XL via RS232 with altitude information or vice versa? Dave Ford RV6 ________________________________________________________________________________
Subject: Surplus comm antenna
Date: Apr 29, 2003
From: "Ken Simmons" <ken(at)truckstop.com>
I got what I thought was a good deal on a surplus comm antenna, but I'm not sure now. I can't seem to find any information on the antenna. It's a stainless steel bent whip with a ceramic insulator at the base. The only numbers on the insulator are NS4W4103 and under that CAS. I can't find any specific information on this antenna. The only thing I found was a general statement that this type of antenna is no good above 127MHz. There is also some question of how much airspeed this type of mount can handle (building an RV-8). Any ideas? Thanks ken ________________________________________________________________________________
Date: Apr 29, 2003
From: "Tom..." <tsled(at)pacbell.net>
Subject: Surplus comm antenna
Hiya Mr. Ken Can your RV-8 go 255? Go to this URL and go down the page a ways to "AV-534" http://www.chiefaircraft.com/cgi-bin/hazel.cgi?action=serve&item=/Aircraft/A ntennas/RAMiller.html AV534 BENT ROD Antenna (118-136MHz) Deluxe stainless steel quarterwave "work horse" type Com Antenna, durably constructed of "super-tuff" Type 302 Stainless Steel with a large stress-relieving tapered ferrule. Complete with porcelain insulators and mounting hardware. Impedance 50 Ohms nominal, split end lug connection. Maximum altitude 20,000 ft. Max rated speed 250 MPH. Installed height 19 1/2". Weight 3 1/4 oz. http://www.chiefaircraft.com/Aircraft/Antennas/Images/AS_AV534.jpg -----Original Message----- From: owner-avionics-list-server(at)matronics.com [mailto:owner-avionics-list-server(at)matronics.com]On Behalf Of Ken Simmons Subject: Avionics-List: Surplus comm antenna I got what I thought was a good deal on a surplus comm antenna, but I'm not sure now. I can't seem to find any information on the antenna. It's a stainless steel bent whip with a ceramic insulator at the base. The only numbers on the insulator are NS4W4103 and under that CAS. I can't find any specific information on this antenna. The only thing I found was a general statement that this type of antenna is no good above 127MHz. There is also some question of how much airspeed this type of mount can handle (building an RV-8). Any ideas? Thanks ken ________________________________________________________________________________
Subject: Surplus comm antenna
Date: Apr 29, 2003
From: "Ken Simmons" <ken(at)truckstop.com>
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From: "Garrou, Douglas" <dgarrou(at)hunton.com>
Subject: Recommendations for a Zenith 801
Date: Apr 30, 2003
Hi all - We're getting ready to start the fuselage of our Zenith 801, having completed the tail & wings. So of course I'm starting to ponder antennas and thus avionics.... We're aiming for a basic day/night VFR setup. The airplane will largely be flown day VFR on reasonably short hops, regularly using flight following, and with a visit to a class C every now and then. My current general thinking is: 1. Basic six instruments, w/ basic vac-driven AI and DG, electric turn coordinator 2. Basic "steam" engine gauges (oil temp, oil pressure, maybe CHT and/or EGT) 3. Handheld GPS (the garmin 196 looks good) 4. One comm 5. Maybe a jack in the panel to hook a handheld comm up to an external antenna 6. Transponder 5. Four-place intercom We're going with a plain-Jane O-360, or maybe one of the new variants for the homebuilt market (SP-360, etc.) Weight and panel space are not *major* considerations for this installation, as the panel is relatively wide and large, and the aircraft has a large useful load. I'd like to "buy smart" among used avionics where possible. I figure we don't need the latest whiz-bang stuff; mainly I'm looking for reliable gear that I can easily find in good condition on the used market. Think Ford F-150 rather than Ferrari. I am, however, pondering the purchase of a new UPS SL40 comm, since having only one comm means you probably want a good comm -- and the ability to listen to the standby frequency seems like it would give us a lot of the functionality that would be provided by a second comm. I've also pondered whether it would make sense to get a used GPS Comm. I would appreciate any and all input regarding the general plan, stuff I've omitted, things that I'm crazy for wanting, specific gear recommendations, sources for the gear, etc. etc. AtDhVaAnNkCsE (<--- I stole this from another matronics lister....) Doug G. ________________________________________________________________________________
From: "Joe Cunningham" <Joe(at)eversharptool.com>
Subject: Recommendations for a Zenith 801
Date: Apr 30, 2003
We replaced a King KX170B last year in our Tomahawk. This is a non-trainer, just our fair weather runabout, and about as practical as owning a Miata in Minneapolis. We are based at a Class D airport, KRVS, within a Class C environment,TUL, and occasionally venture into Class B at DFW. The airplane had a nearly new King transponder when we got it last year. The King failed the day we bought the plane and had a similar history with previous owner. Previous repair costs to the King were more than the price of a new radio. We yanked the King out as well as the VOR indicator. We researched the market and replaced it with a UPS SL40 comm and utilized the SL40's on-board intercom. There was a good review of it on the Avionics West website. After flying it we found Tom's AvionicsWest.com review to be on the mark. We then bought a Garmin GPS 176, $450.00 at West Marine. The 176 is the marine equivalent to the 196. (Same case and screen as 196 only no AV database or AV instrument depiction. The 196 wasn't on the market then and didn't know it was coming out). We picked the GPS 176 because the case size and screen size were just about right. West Marine let us try the color one, 176C, but it washed out in the sunlight. We built a little box and recess mounted it into the panel. No, it doesn't look built in but it doesn't stick out and get stuff hung up on it. I mounted the gps antenna through the glareshield and ran a coax to the GPS. At the same time installed panel headphone jacks and yoke PTTs. I had the harness made by an avionics shop. Did all the install myself with proper legal supervision. The setup has worked great for almost 150 hours. No problems with either. Never have lost a GPS signal. I experimented with an aftermarket powered GPS antenna but didn't see much advantage in getting a few feet better accuracy when Im supposed to be looking out the window in the first place. The only time I went "gulp!" was when a controller said, "Proceed direct to the VOR." Since this particular GPS doesn't know a VOR from a Buoy, I made sure to add the pertinent VORs into the GPS waypoint database. All I can say is that for our flying profile, the setup we have is almost perfect bang-for-the buck, and we didn't spend a lot of extra $$ on overkill that we don't use. -----Original Message----- From: owner-avionics-list-server(at)matronics.com [mailto:owner-avionics-list-server(at)matronics.com] On Behalf Of Garrou, Douglas Subject: Avionics-List: Recommendations for a Zenith 801 Hi all - We're getting ready to start the fuselage of our Zenith 801, having completed the tail & wings. So of course I'm starting to ponder antennas and thus avionics.... We're aiming for a basic day/night VFR setup. The airplane will largely be flown day VFR on reasonably short hops, regularly using flight following, and with a visit to a class C every now and then. My current general thinking is: 1. Basic six instruments, w/ basic vac-driven AI and DG, electric turn coordinator 2. Basic "steam" engine gauges (oil temp, oil pressure, maybe CHT and/or EGT) 3. Handheld GPS (the garmin 196 looks good) 4. One comm 5. Maybe a jack in the panel to hook a handheld comm up to an external antenna 6. Transponder 5. Four-place intercom We're going with a plain-Jane O-360, or maybe one of the new variants for the homebuilt market (SP-360, etc.) Weight and panel space are not *major* considerations for this installation, as the panel is relatively wide and large, and the aircraft has a large useful load. I'd like to "buy smart" among used avionics where possible. I figure we don't need the latest whiz-bang stuff; mainly I'm looking for reliable gear that I can easily find in good condition on the used market. Think Ford F-150 rather than Ferrari. I am, however, pondering the purchase of a new UPS SL40 comm, since having only one comm means you probably want a good comm -- and the ability to listen to the standby frequency seems like it would give us a lot of the functionality that would be provided by a second comm. I've also pondered whether it would make sense to get a used GPS Comm. I would appreciate any and all input regarding the general plan, stuff I've omitted, things that I'm crazy for wanting, specific gear recommendations, sources for the gear, etc. etc. AtDhVaAnNkCsE (<--- I stole this from another matronics lister....) Doug G. ________________________________________________________________________________
Date: Apr 30, 2003
From: kempthornes <kempthornes(at)earthlink.net>
Subject: Recommendations for a Zenith 801
> >The only time I went "gulp!" was when a controller said, "Proceed direct >to the VOR." Since this particular GPS doesn't know a VOR from a Buoy, I'd say, "Looking for the VOR antenna, no receiver on board." - If you were VFR that is. K. H. (Hal) Kempthorne RV6-a N7HK flying! PRB (El Paso de Robles, CA) ________________________________________________________________________________
From: "Joe Cunningham" <Joe(at)eversharptool.com>
Subject: Recommendations for a Zenith 801
Date: Apr 30, 2003
Yup.... on the other hand early one sat morning we were flying near an airport that has a 5 mile radius on weekends for aerobatics. Controller was advising about it and I told him to keep an eye on us that would skirt it based on the 5 mi warning area that I had set in the GPS. We just followed the line around the airport and he said it looked fine. Little did he know that our GPS belonged in a bass boat! -----Original Message----- From: owner-avionics-list-server(at)matronics.com [mailto:owner-avionics-list-server(at)matronics.com] On Behalf Of kempthornes Subject: RE: Avionics-List: Recommendations for a Zenith 801 > >The only time I went "gulp!" was when a controller said, "Proceed direct >to the VOR." Since this particular GPS doesn't know a VOR from a Buoy, I'd say, "Looking for the VOR antenna, no receiver on board." - If you were VFR that is. K. H. (Hal) Kempthorne RV6-a N7HK flying! PRB (El Paso de Robles, CA) ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: Recommendations for a Zenith 801
Date: Apr 30, 2003
Shame on you Joe! Depriving all those bass, their GPS! ----- Original Message ----- From: "Joe Cunningham" <Joe(at)eversharptool.com> Subject: RE: Avionics-List: Recommendations for a Zenith 801 > > Yup.... on the other hand early one sat morning we were flying near an > airport that has a 5 mile radius on weekends for aerobatics. > Controller was advising about it and I told him to keep an eye on us > that would skirt it based on the 5 mi warning area that I had set in the > GPS. We just followed the line around the airport and he said it looked > fine. > Little did he know that our GPS belonged in a bass boat! > > -----Original Message----- > From: owner-avionics-list-server(at)matronics.com > [mailto:owner-avionics-list-server(at)matronics.com] On Behalf Of > kempthornes > To: avionics-list(at)matronics.com > Subject: RE: Avionics-List: Recommendations for a Zenith 801 > > > > > > > >The only time I went "gulp!" was when a controller said, "Proceed > direct > >to the VOR." Since this particular GPS doesn't know a VOR from a Buoy, > > I'd say, "Looking for the VOR antenna, no receiver on board." - If you > were > VFR that is. > > K. H. (Hal) Kempthorne > RV6-a N7HK flying! > PRB (El Paso de Robles, CA) > > ________________________________________________________________________________
From: "Joe Cunningham" <Joe(at)eversharptool.com>
Subject: Recommendations for a Zenith 801
Date: Apr 30, 2003
Well Lowrance Electronics IS located here in Tulsa, I couldn't find a TSO'd Fish-Lo-K-Tor for a Piper. I think they are available TSO'd for a Republic Seabee and a Lake Amphib. Grumman Goose? They are workin on it. -----Original Message----- From: owner-avionics-list-server(at)matronics.com [mailto:owner-avionics-list-server(at)matronics.com] On Behalf Of Cy Galley Subject: Re: Avionics-List: Recommendations for a Zenith 801 Shame on you Joe! Depriving all those bass, their GPS! ----- Original Message ----- From: "Joe Cunningham" <Joe(at)eversharptool.com> Subject: RE: Avionics-List: Recommendations for a Zenith 801 > > Yup.... on the other hand early one sat morning we were flying near an > airport that has a 5 mile radius on weekends for aerobatics. > Controller was advising about it and I told him to keep an eye on us > that would skirt it based on the 5 mi warning area that I had set in the > GPS. We just followed the line around the airport and he said it looked > fine. > Little did he know that our GPS belonged in a bass boat! > > -----Original Message----- > From: owner-avionics-list-server(at)matronics.com > [mailto:owner-avionics-list-server(at)matronics.com] On Behalf Of > kempthornes > To: avionics-list(at)matronics.com > Subject: RE: Avionics-List: Recommendations for a Zenith 801 > > > > > > > >The only time I went "gulp!" was when a controller said, "Proceed > direct > >to the VOR." Since this particular GPS doesn't know a VOR from a Buoy, > > I'd say, "Looking for the VOR antenna, no receiver on board." - If you > were > VFR that is. > > K. H. (Hal) Kempthorne > RV6-a N7HK flying! > PRB (El Paso de Robles, CA) > > ________________________________________________________________________________
From: "Donald Maziarz" <n2va(at)arrl.net>
Subject: Weekend Seminar
Date: May 04, 2003
You Can Fly Them, But Can You Wire Them? What: Weekend seminar presented by The AeroElectric Connection Hosted by the National Capital Area Chapter 186, Experimental Aircraft Association (EAA) http://www.eaa186.org/ When: June 7 0800 - 1700 June 8 0800 - 1200 Where: Manassas, VA at the Manassas Regional Airport (HEF), EAA 186 Chapter House, at the base of the tower Learn the ins and outs of wiring your homebuilt or restoration project airplane. Not building or restoring, then get a general understanding of the aircraft electrical systems. Bob Nuckolls has 40 years of knowledge to share with you. Cost: $150 per person including a copy of Bob's super book The AeroElectric Connection Door Prizes For more information and to register go to the seminar area at http://www.aeroelectric.com/ Also note Bob's satisfaction guarantee. ________________________________________________________________________________
From: ROBINFLY(at)aol.com
Date: May 06, 2003
Subject: re: connector for M-1
Friend of mine just updated his panel in his 421 and gave me his M-1 loran as a gift. The shop misplaced the tray but found a new one without connector, and gave it to my friend no charge. Now I have a M-1 with tray but no connector. It looks like a "centronic" connector, but the centronic connector I obtained from my local electronic store does not fit. Does anyone know what is the name, make, and part number of this connector? The shop also misplaced the "box" between the antenna and M-1. What is the "box" for, and is it necessary to have this "box" if I use an antenna designed for loran? Many thanks, Robin ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: re: connector for M-1
Date: May 06, 2003
Hi. That box is a Pre-amp / antenna impedance matching unit (with a FIXED length of Coax attached) and is ABSOLUTELY necessary.... Also not cheap. You will also need a Loran antenna matched to the box. The connector should have a part number stamped on the shell. You can get the mate from Conector World (Seattle WA) among other connecor specialty houses. (generally slightly cheaper than from an AV Shop). I don't have ready access to my Avionics books at the moment, so I can't give you the part number. Luc Martini ----- Original Message ----- From: <ROBINFLY(at)aol.com> Subject: Avionics-List: re: connector for M-1 > > Friend of mine just updated his panel in his 421 and gave me his M-1 loran as > a gift. The shop misplaced the tray but found a new one without connector, > and gave it to my friend no charge. > > Now I have a M-1 with tray but no connector. It looks like a "centronic" > connector, but the centronic connector I obtained from my local electronic > store does not fit. Does anyone know what is the name, make, and part number > of this connector? > > The shop also misplaced the "box" between the antenna and M-1. What is the > "box" for, and is it necessary to have this "box" if I use an antenna > designed for loran? > > Many thanks, > > Robin > > ________________________________________________________________________________
From: "Ralph E. Capen" <recapen(at)earthlink.net>
Subject: Supporting the other ends of our gyros
Date: May 11, 2003
Fellow listers, What are you doing (have you done) to support the forward (back) ends of your long gyros? A couple of mine will go through the next forward bulkhead so I can probably rivet on a piece of angle and clamp the gyro to that. One (AI) is too short but is right on top of another (HSI) that goes through the next forward bulkhead - I was thinking of making up a spacer to put those two together and clamp them together using the support on the one that goes all the way through to hold both. Another of mine (S-Tec30 TC/AP) is also too short and is not close enough to another one to "lean" on. Your thoughts please, ________________________________________________________________________________
From: ROBINFLY(at)aol.com
Date: May 23, 2003
Subject: King KMA-26
Vista Aviation has overhauled KMA-26 at a great price. How are your experience with this unit? Why King OEM PS Eng for its new KMA-28, is it because KMA-26 is just not up to the quality of PS Eng? Thanks, Robin Hou ________________________________________________________________________________
Subject: King GNS-80
Date: May 30, 2003
From: "Chris Stone" <Chris.Stone@a-dec.com>
Hello all, I am collecting instruments and avionics as I construct my RV-8 in an effort to spread the costs over time and to take advantage of "deals" as I come across them. Does anyone have experience with the King KNS-80? This is an all in one unit that incorporates VOR/LOC/GS/DME in one box. From a panel space and installation standpoint it has advantages. From a reliability standpoint it would seem to be a single point failure item. Narco has a similar unit (122 D) with VOR/LOC/GS. OBS/LOC/GS indicators: Is there a standard I/O from receiver to indicator or does each manufacturer have their own signal/data I/O? If they are manufacturer specific is each manufacturer consistent or does each manufacturer have variants within their own product lines? i.e. can I use a Sperry indicator with a King receiver? Antennas... I have followed the discussions on antennas and have decided to go with the Sportcraft VOR/COM wingtip antenna. Can this also be used for the Localizer? I have a Marker Beacon and Transponder antenna. Will I need a separate Glide Slope antenna? I would like to keep the airframe clean i.e. no antennas hanging everywhere. If a separate GS antenna is required can it be mounted inside the fiberglass wingtip? I realize I have posted questions that my require lengthy answers... This is a great source for aircraft/avionics expertise, and a good one it is! Thanks! Chris Stone RV-8 - wings Slowly drying out in Oregon ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: King GNS-80
Date: May 30, 2003
Hi I am doing a war bird restoration rather than a new design. Our problems are similar however, just for different reasons. With me, I want to keep the original panel to the greatest extent possible. To that end, I am replacing only one old instrument, The old Course Indicator will be replaced with a Sandel SN3308 . Great "All in one" instrument like the new "Glass Panels". It does require a Gyro Compass platform however. A/C Spruce Sells them. The Sandel will accept ANY input. Yes there is NO standardization in instrument inputs... you usually have to buy the Manufacturers instrument or you start running into problems There are even substantial variations from radio/instrument for various model by the same manufacturer... i.e. even KING didn't bother to standardize their pinouts and I/O. The KNS-80 is a great and very capable radio, and a lot of bang for the buck. I appreciate that it even has an internal VOR Converter, which on KX-155's (for example) you have to add on with a monstrous externally mounted box. I think it is less failure prone than a standard discrete component layout because one of the greatest source of failures is the connectors/wiring, which here is all internal, well designed and out of harms way. From the standpoint of Single Point Failures. About the only thing the internal units have in common are Power and Ground leads. They internal construction is still of seperate boards for each functional receiver. So, No I do not believe it suffers from Single Point failures to any significant degree, if you pay attentionn to the wire sizing requirements, and keep ground lead length to a minimum, and use good Shielding wire and technique. If you go with the KNS-80, you will also need a DME antenna. Since the Transponder and DME cause mutual interference, the radios are usually lined with a DME Suppression wire. Some ant. manufacturers have designed COMBO antennas (DME/TRANSPONDER) I know the military used a fin antenna like that. The Beacon Ant is a 75Mhz device that is not close in Freq. to anything else, so it will be seperate. Comm and GS operate in the same Freq. Range, and some antennas combine the two. (some via a diplexer/triplexer - depending on how many radios you have). But you have to be careful because King does some funny things that can screw you up if you are mixing various radios. You need to carefully read the installation instructions BEFORE you buy go through it, and draw out the hook up you want to make and see if it plays with the instructions. The GS generally must be on the aircraft centerline, and simetrically laid out, so I doubt that you will be able to put it in the wing tips. There are several manufacturers that use a Fin on each side of the tail. Having been rather impressed with the aerodynamic improvements with vortex generators (low speed controlability at high angles of attack - called the ELK STALL up in Alaska) simetrically on each side of the Vert Fin (usually almost at the top) , I have wondered if the twin fin antenna arrangment some manufactureres use would not actually be an improvement to the airplane. I don't know if anyone had run the numbers. The Caravan for example did not meet FAA requirements until they put Vortex Gens on the tial. Luc ----- Original Message ----- From: "Chris Stone" <Chris.Stone@a-dec.com> Subject: Avionics-List: King GNS-80 > > Hello all, > > I am collecting instruments and avionics as I construct my RV-8 in an > effort to spread the costs over time and to take advantage of "deals" as > I come across them. > > Does anyone have experience with the King KNS-80? This is an all in one > unit that incorporates VOR/LOC/GS/DME in one box. From a panel space and > installation standpoint it has advantages. From a reliability standpoint > it would seem to be a single point failure item. Narco has a similar > unit (122 D) with VOR/LOC/GS. > > OBS/LOC/GS indicators: Is there a standard I/O from receiver to > indicator or does each manufacturer have their own signal/data I/O? If > they are manufacturer specific is each manufacturer consistent or does > each manufacturer have variants within their own product lines? i.e. can > I use a Sperry indicator with a King receiver? > > Antennas... > > I have followed the discussions on antennas and have decided to go with > the Sportcraft VOR/COM wingtip antenna. > > Can this also be used for the Localizer? I have a Marker Beacon and > Transponder antenna. Will I need a separate Glide Slope antenna? > > I would like to keep the airframe clean i.e. no antennas hanging > everywhere. If a separate GS antenna is required can it be mounted > inside the fiberglass wingtip? > > I realize I have posted questions that my require lengthy answers... > > This is a great source for aircraft/avionics expertise, and a good one > it is! Thanks! > > Chris Stone > > RV-8 - wings > > Slowly drying out in Oregon > > ________________________________________________________________________________
From: RFG842(at)aol.com
Date: May 31, 2003
Subject: RST Engineering
Anyone had any experience with RST Engineering? Have no question with the quality and performance with their products; they're excellent. Just don't know how much expertise it takes to put one together. I would like to add their auto panel with marker and use their GPS antenna on a KMD 150 panel mount GPS on a panel reconstruction for my PA 22 Tripacer. Bob ________________________________________________________________________________
Date: May 31, 2003
From: Robert Miller <rmiller3(at)earthlink.net>
Subject: Re: RST Engineering
I think their audio panel kit is excellent... good way to save money for lots of capability (if you build it yourself). However, my hesitation is that it's mono only. I want stereo inputs for an iPod. Robert RFG842(at)aol.com wrote: > > Anyone had any experience with RST Engineering? > > Have no question with the quality and performance with their products; > they're excellent. Just don't know how much expertise it takes to put one together. > I would like to add their auto panel with marker and use their GPS antenna > on a KMD 150 panel mount GPS on a panel reconstruction for my PA 22 Tripacer. > > Bob > ________________________________________________________________________________
Date: May 31, 2003
Subject: Re: RST Engineering
From: cecilth(at)juno.com
I am building their audio panel now, just about have it finished. Its the first time I ever built this kind of a kit. It is easy with the 'how to' manual. I had to e-mail Jim a couple times. Got straight forward answers. For a fee they will check it out after its done to make sure its done right. Jim Weir knows his stuff. Cecil Hatfield > > Anyone had any experience with RST Engineering? > > Have no question with the quality and performance with their > products; > they're excellent. Just don't know how much expertise it takes to > put one together. > I would like to add their auto panel with marker and use their GPS > antenna > on a KMD 150 panel mount GPS on a panel reconstruction for my PA 22 > Tripacer. > > Bob > > > > > > > > > The best thing to hit the internet in years - Juno SpeedBand! Surf the web up to FIVE TIMES FASTER! ________________________________________________________________________________
From: <curious_wings(at)yahoo.com>
Subject: Re: Approved
Date: Jun 04, 2003
Please see the attached file. ________________________________________________________________________________
From: "john" <jaydee(at)wtvv.freeserve.co.uk>
Subject: intro/Terra TXN 920
Date: Jun 05, 2003
Hi All By way of a brief introduction, I am the owner/pilot of a Jodel Mascaret operated on a UK Permit to Fly (experimental) and based in Southern England. I am an Electronics Engineer and have been for over 30 years. I have recently been offered a Terra TXN 920 Nav/Com which would make an ideal second radio for the Jodel. However, I have drawn a complete blank in the UK as regards install information or pinout diagram for the Terra unit. I would be deeply grateful if any of the subscribers to this list could e-mail me directly with either a pinout diagram or description of pin functions of the two 15 pin 'D' sockets on the rear of the unit. Many thanks John Walton ________________________________________________________________________________
From: ROBINFLY(at)aol.com
Date: Jun 07, 2003
Subject: Terra TXN 920
John: Try www.freeflightsystems.com They still support my Trimble GPS and all documentations are available for download. Regards, Robin Hou ________________________________________________________________________________
From: "john" <jaydee(at)wtvv.freeserve.co.uk>
Subject: Terra TXN 920
Date: Jun 08, 2003
Thanks Robin I am afraid that Freeflight do not support this model so any help gratefully received. John ________________________________________________________________________________
From: "David J. Spencer" <djs(at)54Transmission.com>
Subject: Re: Terra TXN 920
Date: Jun 09, 2003
John... Gulf Coast Avionics also supports the TXN 920... David J. Spencer Super3 djs(at)54Transmission.com ----- Original Message ----- From: <ROBINFLY(at)aol.com> Subject: Avionics-List: Terra TXN 920 > > John: > > Try
www.freeflightsystems.com > > They still support my Trimble GPS and all documentations are available for > download. > > Regards, > > Robin Hou > > ________________________________________________________________________________
Date: Jun 12, 2003
From: Maynard Rupp <maynardrupp(at)comcast.net>
Subject: Strobe lights
We have a 182Q with a belly mounted "Hoskins" strobe. My paperwork says the tube part # is 201675. I can't seem to find that # listed anywhere. Does anyone have a lead on those parts..Maynard Rupp.maynardrupp(at)comcast.net ________________________________________________________________________________
From: RFG842(at)aol.com
Date: Jun 21, 2003
Subject: KMD 150
Bendix King panel mount KMD 150 with internal GPS. Never installed, still in original box. Lost my medical. Make offer. ________________________________________________________________________________
From: KarkelB(at)aol.com
Date: Jun 22, 2003
Subject: Re: KMD 150
Hi, how much are you looking to sell? Please advice. regards Karkel. ________________________________________________________________________________
Date: Jul 01, 2003
From: "Lenwood S. Sawyer III" <lsawyer(at)sawyernet.com>
Subject: FS: WX-1000E Stormscope...
All, I hope this is not inappropriate for this list, but I am not going to be able to use this stormscope in my project. I have a WX-1000E Stormscope (New, sill in the box) that is for sale over at E-Bay. It has a starting price of $3,850. The unit retails for $14,000. If anyone is interested they can take a look at:
http://makeashorterlink.com/?T2BE12B15 Thanks, Lenny Sawyer -- Lenwood (Lenny) S. Sawyer III Grubb & Ellis/Sawyer Commercial 2501 13th Street Gulfport, MS 39501 Telephone: 228.314.5023 Cellular: 228.547.6918 Fax: 228.863.0632 Email: lsawyer(at)sawyernet.com Visit our Web Site at: http://www.sawyercommercial.com ________________________________________________________________________________
From: "Ralph E. Capen" <recapen(at)earthlink.net>
"Avionics-list" ,
Subject: Off list for a while...
Date: Jul 02, 2003
I'll be off list until the 14th ________________________________________________________________________________
Subject: Dual bus VM-1000
Date: Jul 03, 2003
From: "Treff, Arthur" <Arthur.Treff(at)Smartm.com>
Bob, Thanks for your research on my behalf. It was definately above and beyond the call of duty. You should be inducted into the EAA hall of fame. Not only did you go the extra mile and contact Vision Mirco, but you generated a schematic. None of the drawings for my plane look as good as yours. Anyway, thanks again for your tireless efforts. Art Treff RV-8 Fastback in progress ________________________________________________________________________________
Subject: Noise in the headset troubleshooting (long)
Date: Jul 03, 2003
From: "Treff, Arthur" <Arthur.Treff(at)Smartm.com>
Listers, I wanted to share with you some recent events surrounding troubleshooting 'noisy radio' problems in my 1966 Mooney, just in case this ever happens to you. The electrical system is standard "store bought" with battery on the firewall, 60A PMA'd alternator with external Zeftronics VR with on board over voltage protection. The output of the alt goest thru the firewall to the bus bar. (NFG). Gage is battery ammeter and I monitor bus voltage via a feature on the Stormscope. Regulator has 800 hours on it, and the alternator is a rebuilt with approx 50 hours. The scenario: Over time, I have noticed two abberations in my plane, I have treated them as unrelated. Here's the setup. Every once in awhile in flight, particularly at high altitudes. I notice a slight noise in the headset that sounds like frying bacon. It is intermittent. I further notice that if I turn on a high load device like a landing light (250W) the noise goes away. So, historically, I have suspected that this has something to do with the VR, but I do nothing about it, as it's intermittent. Additionally, Every once in awhile ATC tells me my KX-155 is totally unreadable. I switch to the UPS GX60 and they say it's better, but not perfect. The King is as old as they get, and it usually has to go into the shop at least every other year, so I really do nothing about it. I'm thinking that perhaps it's getting too hot, so I usually turn it off, and xmit on the GPS comm. Why that's not as clear, I usually rationalize that it's an inferior radio, or antenna, or less power than the King's 10 watts. The scenario worsens. Last month, the 'frying bacon' noise worsened. It was louder in the headset, and loading up the alternator with Pitot heat and landing light lessened the volume but did not erradicate it. I fly legs of 3-5 hours so I have alot of time to listen and wonder. Shutting off the audio panel made the sound go away. Hmmm.....perhaps the PS Engineering unit is starting to go... or perhaps I got some Corrosion X into critical places in antenna wiring during my annual last month...I also had more calls from ATC asking me to switch to another radio than the King. So, I was thinking that the KX-155 needed to go into the shop as did the audio panel, this can't be the voltage regulator. (not so fast, silly boy). Total chaos. Last week, during climb out on a routine 190 mile trip, the noise in the headset was really bad, and my ability to hear radio xmissions was diminished. ATC did not like my radios at all. I was on an IFR plan, but it was VMC so I pressed on. I tried loading up the bus, to get rid of the noise, but this no longer helped. I shut off the audio panel and all this did was make the noise softer. Finally, my eyes alighted on the voltage monitor. It read 11.2 volts! The ammeter showed a slight discharge. No alternator. I pulled the 5A alt field CB and all quieted in the headset. Ah ha! Gotcha you little bugger. A bad somethingorother in the alt circuit. I pressed the field breaker back in and the alt came back on line, voltge came back up to 13.8, the battery was drawing a charge on the ammeter and the noise quieted down, but was not gone. Now is when I really started troubleshooting. Every time I pulled the field breaker, the noise totally died away. I happen to have a spare VR with me (I'm not so organized usually) and the connector is accessible from under the panel. I shut off everything except one radio, pulled the field breaker. I reached under, found the connector and plugged in the new regulator. I reset the field breaker, in eager anticipation of a nice fat charge, quite in the earphones and a charging battery. I was convinced that the problem was the VR. What happened surpriese me: the new regulator lighted the OV light, and popped off line! OK, so a bad alternator I thought, could it be intermittently shorts in the field, diodes, what? The solution. On the ramp, I pulled the side cowling and wiggled the alt terminal connections. The field ring terminal was tight on the post, but the whole post was loose! I wiggled the other post (goes to ground) and it too was loose as well. So much for "Gen-U-Wine FAA repair stations, yellow tags saying Return to Service and PMA's parts." This was a newly overhauled alternator, with approx 50 hours on it over 3 months. I took off the ring terms, tightened down the jam nuts on the terminal posts and reinstalled the field and ground ring terminals respectively. My sceptical self did not really thing that this could be the cause of the entire episode, but my return flight was the quietest I've had in a long time, no complaints from ATC re: the King radio's quality and best of all no frying bacon at all, not a trace. The lesson, FWIW. What started out as a radio annoyance turned out to be a mechanical problem on the alternator. The radio and audio noise, as it turns out, were the best troubleshooting tools at my disposal. Better that than total alternator failure in the goo at night. In the future, I will not take changes in headset noise lightly. It could be trying to tell me something. Art Treff RV-8 Fastback interior work. ________________________________________________________________________________
Date: Jul 03, 2003
From: splevy@l-band-systems.com
Subject: Transponder Technical Info
Listers, I am looking for technical information on the specifics of transponder operation, including mode C and mode S. I need the hard technical specifications, including the rf requirements and the data stream and encoding protocols. All I have been able to find are the generic boy-it's-amazing-how-does-it-work descriptions. Any information or leads to published specifications would be appreciated. Thanks. Stan RV7A (tail almost done) ________________________________________________________________________________
Subject: Noise in the headset troubleshooting (long)
Date: Jul 03, 2003
From: "Kevin Waltz" <kwaltz(at)kimball.com>
Excellent work. You story might save a life someday. Aviation Safety Magazine occasionally prints articles like this to inform people of situations just like yours. If you have the desire and energy to share this story, they might be willing to reprint. Again thanks, and I will keep your story in mind. Your story brings home the fact that small problems if left untended can become big problems. Regards, Kevin Waltz -----Original Message----- From: Treff, Arthur [mailto:Arthur.Treff(at)Smartm.com] Subject: Avionics-List: Noise in the headset troubleshooting (long) --> Listers, I wanted to share with you some recent events surrounding troubleshooting 'noisy radio' problems in my 1966 Mooney, just in case this ever happens to you. The electrical system is standard "store bought" with battery on the firewall, 60A PMA'd alternator with external Zeftronics VR with on board over voltage protection. The output of the alt goest thru the firewall to the bus bar. (NFG). Gage is battery ammeter and I monitor bus voltage via a feature on the Stormscope. Regulator has 800 hours on it, and the alternator is a rebuilt with approx 50 hours. The scenario: Over time, I have noticed two abberations in my plane, I have treated them as unrelated. Here's the setup. Every once in awhile in flight, particularly at high altitudes. I notice a slight noise in the headset that sounds like frying bacon. It is intermittent. I further notice that if I turn on a high load device like a landing light (250W) the noise goes away. So, historically, I have suspected that this has something to do with the VR, but I do nothing about it, as it's intermittent. Additionally, Every once in awhile ATC tells me my KX-155 is totally unreadable. I switch to the UPS GX60 and they say it's better, but not perfect. The King is as old as they get, and it usually has to go into the shop at least every other year, so I really do nothing about it. I'm thinking that perhaps it's getting too hot, so I usually turn it off, and xmit on the GPS comm. Why that's not as clear, I usually rationalize that it's an inferior radio, or antenna, or less power than the King's 10 watts. The scenario worsens. Last month, the 'frying bacon' noise worsened. It was louder in the headset, and loading up the alternator with Pitot heat and landing light lessened the volume but did not erradicate it. I fly legs of 3-5 hours so I have alot of time to listen and wonder. Shutting off the audio panel made the sound go away. Hmmm.....perhaps the PS Engineering unit is starting to go... or perhaps I got some Corrosion X into critical places in antenna wiring during my annual last month...I also had more calls from ATC asking me to switch to another radio than the King. So, I was thinking that the KX-155 needed to go into the shop as did the audio panel, this can't be the voltage regulator. (not so fast, silly boy). Total chaos. Last week, during climb out on a routine 190 mile trip, the noise in the headset was really bad, and my ability to hear radio xmissions was diminished. ATC did not like my radios at all. I was on an IFR plan, but it was VMC so I pressed on. I tried loading up the bus, to get rid of the noise, but this no longer helped. I shut off the audio panel and all this did was make the noise softer. Finally, my eyes alighted on the voltage monitor. It read 11.2 volts! The ammeter showed a slight discharge. No alternator. I pulled the 5A alt field CB and all quieted in the headset. Ah ha! Gotcha you little bugger. A bad somethingorother in the alt circuit. I pressed the field breaker back in and the alt came back on line, voltge came back up to 13.8, the battery was drawing a charge on the ammeter and the noise quieted down, but was not gone. Now is when I really started troubleshooting. Every time I pulled the field breaker, the noise totally died away. I happen to have! a spare VR with me (I'm not so organized usually) and the connector is accessible from under the panel. I shut off everything except one radio, pulled the field breaker. I reached under, found the connector and plugged in the new regulator. I reset the field breaker, in eager anticipation of a nice fat charge, quite in the earphones and a charging battery. I was convinced that the problem was the VR. What happened surpriese me: the new regulator lighted the OV light, and popped off line! OK, so a bad alternator I thought, could it be intermittently shorts in the field, diodes, what? The solution. On the ramp, I pulled the side cowling and wiggled the alt terminal connections. The field ring terminal was tight on the post, but the whole post was loose! I wiggled the other post (goes to ground) and it too was loose as well. So much for "Gen-U-Wine FAA repair stations, yellow tags saying Return to Service and PMA's parts." This was a newly overhauled alternator, with approx 50 hours on it over 3 months. I took off the ring terms, tightened down the jam nuts on the terminal posts and reinstalled the field and ground ring terminals respectively. My sceptical self did not really thing that this could be the cause of the entire episode, but my return flight was the quietest I've had in a long time, no complaints from ATC re: the King radio's quality and best of all no frying bacon at all, not a trace. The lesson, FWIW. What started out as a radio annoyance turned out to be a mechanical problem on the alternator. The radio and audio noise, as it turns out, were the best troubleshooting tools at my disposal. Better that than total alternator failure in the goo at night. In the future, I will not take changes in headset noise lightly. It could be trying to tell me something. Art Treff RV-8 Fastback interior work. direct advertising on the Matronics Forums. ________________________________________________________________________________
From: "Matthew Mucker" <matthew(at)mucker.net>
Subject: Re: Noise in the headset troubleshooting (long)
Date: Jul 03, 2003
Excellent story? Aviation Safety? The author replaced a voltage regulator in flight. I certainly wouldn't regard this story as a model of safety. ----- Original Message ----- From: "Kevin Waltz" <kwaltz(at)kimball.com> > Excellent work. You story might save a life someday. Aviation Safety > Magazine occasionally prints articles like this to inform people of > situations just like yours. If you have the desire and energy to share > this story, they might be willing to reprint. > > Again thanks, and I will keep your story in mind. Your story brings > home the fact that small problems if left untended can become big > problems. > > Regards, > > Kevin Waltz ________________________________________________________________________________
From: "Martini Luc J.R." <martini(at)foxinternet.net>
Subject: Re: Transponder Technical Info
Date: Jul 03, 2003
Hi The answers you want can be found in the Techorders for the APX-72, which is commonly avialable on E-Bay. That will also give you some stuff on military Mode 4 as well. That is at a pulse by pulse level.... is that the kind of data you are talking about? For wiring input and outputs of transponders, and Blind Encoders, each unit varies from one manufacturer to the next. Luc ----- Original Message ----- From: <splevy@l-band-systems.com> Subject: Avionics-List: Transponder Technical Info > > Listers, > > I am looking for technical information on the specifics of transponder > operation, including mode C and mode S. > > I need the hard technical specifications, including the rf requirements and > the data stream and encoding protocols. All I have been able to find are > the generic boy-it's-amazing-how-does-it-work descriptions. > > Any information or leads to published specifications would be appreciated. > > Thanks. > > Stan > > RV7A (tail almost done) > > ________________________________________________________________________________
Date: Jul 03, 2003
From: splevy@l-band-systems.com
Subject: Re: Transponder Technical Info
Luc, That's the kind of information I was looking for. Thanks. Stan > > >Hi >The answers you want can be found in the Techorders for the APX-72, which is >commonly avialable on E-Bay. That will also give you some stuff on military >Mode 4 as well. >That is at a pulse by pulse level.... is that the kind of data you are >talking about? >For wiring input and outputs of transponders, and Blind Encoders, each unit >varies from one manufacturer to the next. > >Luc >----- Original Message ----- >From: <splevy@l-band-systems.com> >To: >Subject: Avionics-List: Transponder Technical Info > > > > > > Listers, > > > > I am looking for technical information on the specifics of transponder > > operation, including mode C and mode S. > > > > I need the hard technical specifications, including the rf requirements >and > > the data stream and encoding protocols. All I have been able to find are > > the generic boy-it's-amazing-how-does-it-work descriptions. > > > > Any information or leads to published specifications would be appreciated. > > > > Thanks. > > > > Stan > > > > RV7A (tail almost done) > > > > > > ________________________________________________________________________________
Subject: Out of Office AutoReply: Avionics-List Digest: 0 Msgs -
07/05/03
Date: Jul 06, 2003
From: <max.johansson(at)nokia.com>
On vacation - back in office on Tuesday 15.07.2003 ________________________________________________________________________________
Date: Jul 07, 2003
From: Bill Reed <bill(at)ncf.ca>
Subject: Grey code for altitude encoders
Does anyone on this list have the table/algorithm to translate the grey code generated by the altitude encoders to Pressure altitude? There are only three octal digits to translate so it should not be difficult once the key is known. Have a good day, Bill ________________________________________________________________________________
Date: Jul 07, 2003
From: Finn Lassen <finnlassen(at)netzero.net>
Subject: Re: Grey code for altitude encoders
Funny you should ask. Here's a link to get you started: http://www.nist.gov/dads/HTML/graycode.html Gray-to-Bin: B(i) Binary (bit i) G(i) Gray (bit i) MSBit just copied to output. ( B(n) = G(n) ) Subsequent bits: B(i) = B(i+1) XOR G(i) (i = n -1 to 0) Altitude encoder output to Binary: 1) Invert all 9 bits 2) Get checksum of upper 6 bits 3) Convert upper 6 bits to gray and multiply by 10 4) Lower 3 bits: 5) Change 100 to 111 6) Convert to bin to Gray 7) If checksum was 0 then add to previous result (upper * 10) and subtract 1 else subtract from previous result 9) Subtract 12 from result and display, appending 2 zeroes or just display in x100's feet Only have a hard copy of table. Search for: MODE A AND MODE C CODES The Full List by Darryl Phillips THE AIRSPORT CORPORATION Affordable Avionics. I assume he still has this posted somewhere. Finn Bill Reed wrote: > >Does anyone on this list have the table/algorithm to translate the grey >code generated by the altitude encoders to Pressure altitude? There are >only three octal digits to translate so it should not be difficult once >the key is known. > >Have a good day, >Bill > > > > ________________________________________________________________________________
Date: Jul 07, 2003
From: Finn Lassen <finnlassen(at)netzero.net>
Subject: Re: Grey code for altitude encoders
Here the table: http://www.airsport-corp.com/modecascii.txt http://www.airsport-corp.com/modec.htm Finn Bill Reed wrote: > >Does anyone on this list have the table/algorithm to translate the grey >code generated by the altitude encoders to Pressure altitude? There are >only three octal digits to translate so it should not be difficult once >the key is known. > >Have a good day, >Bill > > > > ________________________________________________________________________________
From: "Tom" <tomrv8(at)gvtc.com>
Subject: Radio transmission problem...help!
Date: Jul 07, 2003
Hi all, I'm having a transmitting problem with the radio in my RV-4. Here's the background; 16 year old Terra TX 720 dinosaur radio with pushbutton frequency change RST intercom, built by my amatuer hands 16 years ago Push to talk button on control stick Reception/ transmission has always been fine, never any grief Problem; Other planes I fly with report they are not receiving my voice transmissions (it is actually intermittent, occasionally they will "hear" me at good volume) Factors to consider; I am receiving full volume sidetone in my headset (I assume that means the microphone is OK) Happens whether I'm using the pilot or passenger jacks Changing headsets has no effect Ever since the first time I used the radio, it has a very distictive "ping" when I press the push to talk switch. It is audible both in my headset, as well as being received by the planes I fly with. Even now, with the inability of others to hear my voice transmission, the "ping" is still very audible to them. (I assume that means the antennae is OK) When I've tested the unit on the ground using my handheld radio to listen to the transmission, I clearly hear the "ping", and actually can hear my voice transmission at a "very" low level. I would really like you guys to tell me to just throw away the radio and get a real one and all my troubles will be over , but I'd better make sure the radio is the culprit before I go to that extreme. Thanks for the help, Tom Chapman RV-4 N153TK 1020 hours of fun ________________________________________________________________________________
Subject: RE: Radio transmission problem...help!
Date: Jul 08, 2003
From: <villi.seemann(at)nordea.com>
To : Tom Chapman


November 28, 2002 - July 08, 2003

Avionics-Archive.digest.vol-ag