Avionics-Archive.digest.vol-ag
November 28, 2002 - July 08, 2003
________________________________________________________________________________
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
________________________________________________________________________________
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
________________________________________________________________________________
From: | Matt Dralle <dralle(at)matronics.com> |
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.
________________________________________________________________________________
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.
________________________________________________________________________________
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> |
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
________________________________________________________________________________
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 |
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 |
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 $2K
installation
> labor for one GPS/Com w/ new antenna & calbe I paid 2 years ago). I did
not
> remove the antennas, but "ohm" the antenna connectors' shield (ground?)
and
> A/C skin and both read .2 ohm.
>
> I also found that when I "ohm" the coax connectors on both antenna (not on
> cable), the weak com antenna has no connection between the center and
shield
> (ground?) but the good com antenna reads .4 ohm between the center and
> shield. Does it sound right? If the good com antenna and the A/C ground
are
> connected (w/ .4 ohm), how can it be the "good" com antenna?
>
> Robin Hou
> E35 Bo,
> N7303B
>
>
________________________________________________________________________________
From: | Benford2(at)aol.com |
Subject: | Intercom wiring ??? |
I bought a PS Engineering PM 1000ll and went to install it,and low and behold
there where no schematics in the box. So I called them and they said " take
it to an avionics shop" and then he told me that there is no warrenty on
their unit unless I bought a harness from them for 200.00$. 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.
________________________________________________________________________________
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.
>
>
________________________________________________________________________________
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.
________________________________________________________________________________
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
________________________________________________________________________________
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
>
>
________________________________________________________________________________
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 |
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.
________________________________________________________________________________
From: | Tim & Diane Shankland <tshank(at)megsinet.net> |
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
________________________________________________________________________________
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 |
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
>
>
>
>
>
>
________________________________________________________________________________
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
________________________________________________________________________________
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?
________________________________________________________________________________
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
________________________________________________________________________________
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
________________________________________________________________________________
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
________________________________________________________________________________
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 |
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 |
does anyone know where to get the plastic gears for Narco com's---tnx Paul
________________________________________________________________________________
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
________________________________________________________________________________
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
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
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
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.
>
>
________________________________________________________________________________
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
________________________________________________________________________________
Subject: | Re: Be Aware FAA can pull anyones license without recourse.. |
SECURITY
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 |
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 |
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 |
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 |
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 |
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).
________________________________________________________________________________
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
________________________________________________________________________________
From: | John Myers <jmyers(at)powernet.org> |
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> |
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 |
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> |
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> |
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
>
>
________________________________________________________________________________
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 .
________________________________________________________________________________
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
________________________________________________________________________________
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
________________________________________________________________________________
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 |
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) |
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) |
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) |
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) |
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) |
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) |
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) |
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) |
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) |
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) |
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) |
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) |
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) |
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
> > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
________________________________________________________________________________
From: | Philip Rice <ricephil(at)pld.com> |
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
________________________________________________________________________________
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
---------------------------------
________________________________________________________________________________
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> |
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> |
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 |
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
________________________________________________________________________________
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 |
From: | "Ken Simmons" <ken(at)truckstop.com> |
Tm93IEknbSByZWFsbHkgYW5ub3llZCB0aGF0IEkgY291bGRuJ3QgZmluZCB0aGlzLiBUbyBiZSBo
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________________________________________________________________________________
From: | "Garrou, Douglas" <dgarrou(at)hunton.com> |
Subject: | 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.
________________________________________________________________________________
From: | "Joe Cunningham" <Joe(at)eversharptool.com> |
Subject: | Recommendations for a Zenith 801 |
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.
________________________________________________________________________________
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 |
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 |
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 |
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> |
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 |
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 |
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 |
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 |
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
________________________________________________________________________________
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> |
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
>
>
________________________________________________________________________________
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
________________________________________________________________________________
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
>
________________________________________________________________________________
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> |
Please see the attached file.
________________________________________________________________________________
From: | "john" <jaydee(at)wtvv.freeserve.co.uk> |
Subject: | intro/Terra TXN 920 |
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 |
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> |
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 |
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
>
>
________________________________________________________________________________
From: | Maynard Rupp <maynardrupp(at)comcast.net> |
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
________________________________________________________________________________
Bendix King panel mount KMD 150 with internal GPS.
Never installed, still in original box.
Lost my medical. Make offer.
________________________________________________________________________________
Hi,
how much are you looking to sell? Please advice.
regards Karkel.
________________________________________________________________________________
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... |
I'll be off list until the 14th
________________________________________________________________________________
Subject: | Dual bus VM-1000 |
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) |
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.
________________________________________________________________________________
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) |
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) |
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 |
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)
>
>
________________________________________________________________________________
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
From: | <max.johansson(at)nokia.com> |
On vacation - back in office on Tuesday 15.07.2003
________________________________________________________________________________
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
________________________________________________________________________________
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
>
>
>
>
________________________________________________________________________________
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! |
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! |
From: | <villi.seemann(at)nordea.com> |
To : Tom Chapman
November 28, 2002 - July 08, 2003
Avionics-Archive.digest.vol-ag