---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 01/28/08: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:28 AM - Re: Dumb questions (AM radio) () 2. 05:25 AM - Re: Dumb questions (Robert L. Nuckolls, III) 3. 05:56 AM - Re: Z13-8 N P-Mags (Robert L. Nuckolls, III) 4. 05:58 AM - Re: TNC connections (Robert L. Nuckolls, III) 5. 08:22 AM - Alternator Problems (algrajek) 6. 11:46 AM - Soliciting knowledgable comments about Eagle EMS (Larry L. Tompkins, P.E.) 7. 03:46 PM - Firewall penetration (rvtach) 8. 04:58 PM - Re: Firewall penetration (RV10 4JF) 9. 05:34 PM - Re: Firewall penetration (Dale Ensing) 10. 05:41 PM - Thumb screws for plastic hoods (Allen Fulmer) 11. 06:37 PM - Note 8 in App_ ZR11 M (Emrath) 12. 07:21 PM - Re: Firewall penetration (Charlie England) 13. 07:53 PM - Re: Firewall penetration (Ernest Christley) ________________________________ Message 1 _____________________________________ Time: 04:28:02 AM PST US From: Subject: AeroElectric-List: Re: Dumb questions (AM radio) >From: "Richard Girard" >Re: AeroElectric-List: Dumb questions >personal (habit) of listening to broadcast > radio on the ADF. >Bob Dingley Bob, I assume you are an AM radio junkie? My suggestion/opinion DO NOT buy a big heavy car radio/CD player and mount it in the panel. Why? Its heavy and not needed to listen to radio. My suggestion is MOST all intercoms have an audio input with a little phone jack. You can connect a little portable AM/FM battery powered radio or iPod / MP3 player or any audio source you desire to it. The antenna can just be the internal antenna or small whip, no need to install antennas and run coax and add drag/weight. The antenna in cockpit can pick up plenty of signal through plexi. I use a little high quality portable AM/FM radio. It has digital tuning and scanning. The wire from the radio to the head phone acts as the antenna. I just used a little phone to phone jumper cable, plugging it into the intercom, and had radio. It worked very well. I like listening to some radio shows or sports on a cross country. No need to take up the panel with a big automotive unit. Keep it light and keep it simple. Plan on a good intercom and good head sets. The nice thing is when the COM radio kicks in the intercom cuts the entertainment audio out. When the COM is quite, the entertainment fades back in. Go to Radio Shack and search "AM/FM Pocket Radio". There are 23 models to pick from $10-$30. Check out the Grundig Mini 300 AM/FM/SW Pocket Radio, its pretty cool and has a rubber duckie antenna and SW radio, for $30. The DOWN side with radio, as you know, you out fly the station. Of course super powerful AM radio stations at night, with "skip" can be listened to for a long time time, if you are flying towards them. "The Captains Guide", has list of high powered AM radio stations around the county. I can't stand AM radio for the most part. Now I only use my iPod with +2000 songs and 'pod casts'. [Pod cast are almost anything and often entertainment programs, like radio shows. You download them from the web, often for free. For example I download a NPR program or two on my iPod.] ADF is dead, heavy, bulky and on deaths door with GPS. George ATP/CFI (RV7 still pounding) PS: per other suggestions XM radio is the bomb but cost monthly subscription. However if you have a protable XM radio unit, it can plug into the same intercom audio/aux input the protable AM/FM radio does. --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. ________________________________ Message 2 _____________________________________ Time: 05:25:42 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Dumb questions At 04:21 PM 1/27/2008 -0600, you wrote: >Bob, I'm no expert, but I did learn this from one. Some automotive audio >systems use completely separate grounds for each channel. For that you'd >have to rewire your headphones and run three jacks instead of two. This >info may be old, it was a few years ago and things move on, but it never >hurts to ask the sales guy or look at the wiring layout of any system >you're thinking of buying. > >Rick > >On Jan 27, 2008 2:49 PM, <MaxNr@aol.com> wrote: >>I have been sitting in the back row on this list, hoping to learn >>something. I was born without any electronic genes. I am building an all >>metal light sport plane.(Zenith) Right or wrong, I developed the habit >>(over five decades of personal, military and commercial flying) of >>listening to broadcast radio on the ADF. I'm thinking that I need to >>install an of the shelf automobile radio in my project. No second hand >>Ebay ADF's. My two questions are: Will I fry the radio if I use only a >>headset and no speakers? About the antenna. I know that I should mount it >>vertically, but it must withstand airspeed excursions to Vne >>(156kts/180mph) without going L shaped. I've come up with somehow jamming >>it inside the canopy, or insulating it and mounting against the landing >>gear, or inside some kind of tubular mast on the belly. I did come across >>a NOS Volkswagen telescoping antenna in my shop. It would be great if >>that Lyc carburetor turns up again the same way. Somebody stop me if I'm >>on the wrong track. This isn't the most pressing problem out there, but >>all suggestions are appreciated. What Rick is referring to is the differential balanced PAIR of wires that goes to each speaker. This is a technique that allows TWO amplifiers to drive both wires of a speaker out of phase with each other. This effectively doubles the potential peak-to-peak voltage to drive each speaker . . . 4x the watts without having to resort to power supply boosters or very low impedance speakers. It also eliminated the need for an output coupling capacitor . . . a fat passive rascal that was a necessary inconvenience. See: http://www.aeroelectric.com/Pictures/Schematics/LM4752.pdf Here's a "single ended" stereo amplifier. Note the 1000 uF capacitors in series with the speakers. Note also that the speakers are grounded on one side. See: http://www.aeroelectric.com/Pictures/Schematics/LM4950.pdf Here we see two amplifiers wired to each side of the speaker. No 1000 uF capacitor needed. Most car radios use a similar scheme with one pair of dif-amps for the front speakers and another pair for the rear speakers, a total of eight, ungrounded wires. There are perhaps a half-dozen ways to adapt the speaker outputs of a radio to the headphone inputs of the intercom. However, many automotive radios have line output features for taking stereo audio to external amplifiers. These are already in the ballpark for connection directly to the stereo inputs of an intercom system. They're already single-ended and shielded against case ground for the radio. I'll suggest you seek a radio with the AUX OUTPUT feature and start from there. If this proves unsatisfactory, I can show you how to craft an interface network to go between your radio's speaker outputs and the stereo inputs of your intercom. The antenna is another deal entirely. Vertically polarized, medium wave signals run along the ground and work really fine with short antennas on ground based vehicles. Once you leave the ground, performance for a short whip antenna degrades. The antenna input to an automotive AM receiver is a unique beast. It's a very high impedance port that is performance degraded by CAPACITY. If you cut the feedline open on a car radio antenna, you may find that the center conductor is a very small single strand of wire supported down the center of the coaxial cable by a hollow plastic tube. This high-impedance coax was supplied to us in large spools at Cessna way back when . . . it was necessary for the purpose of extending the sense antenna feeder from radio on the panel to a feed-through insulator on the cabin roof. I suspect that this input philosophy is still used. Off-the-shelf car antennas come with a run of this specialized "coax" that is already terminated to mate with jacks on radio and base of antenna. The 'ideal' AM receiver antenna for airborne applications would be the "ferrite loopstick" described in the 'Connection's section on antennas. This is an H-field antenna that is not unlike that which your ADF uses to find bearing of an incoming signal. Unfortunately, the loopstick IS directional. Unless you can rotate the antenna, you would need 2 or three of the things along with an ability to switch between them as well as tune them to the station's frequency for best reception. This calls for some experimentation. Ideally, your radio's antenna input would be characterized for performance with a longer piece of coax (higher capacity) and a relatively long wire antenna not unlike that used for sense antennas of the earliest ADFs. In this respect, the ADF receivers and AM radio receivers have a great deal in common with respect to crafting a high performance antenna with an exceedingly small size compared to the wavelength of energy being tapped. Crafting a "high speed" whip antenna has it's challenges. My first thought is that actual orientation of the antenna would have little effect on performance. I think I'd experiment with a "trailing wire" . . . a 5' of wire that attaches to a suitable fitting just before you taxi out. Or, consider crafting a j-bend antenna, not unlike that used for marker beacons. Use the standard AM radio antenna that's a solid rod. Heat it with a torch so that you can put a 90-degree bend in it about 6" from the base. Then allow it to fair rearward and support the tip on an insulated mast of some variety. Check with the automotive radio/audio shops for an antenna with longer than usual coax cable. This might be for a truck, van or RV. The antenna can't be a telescoping variety . . . solid stainless rod is called for. But then, depending on your particular installation, perhaps a standard automotive antenna for a sedan will have enough coax. See what it takes to install it on the belly modified and supported as described above. Let us know how it works out! Bob . . . ________________________________ Message 3 _____________________________________ Time: 05:56:43 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z13-8 N P-Mags At 01:06 AM 1/28/2008 -0500, you wrote: > >You might think wiring up an electronic mag might be simple :-( > >Replacing the S700-2-10 with a S700-2-1 as I indicated in my previous >post isn't the correct solution. . . . >My current plan is to use four of the simplest single-pole on-off >switches, two for power and two for p-lead grounding, plus a push >button for start. So that is a total of five switches, but much >simpler and cheaper components and the plane will still fly if any one >of them fails. Hmmmm . . . I take it that you have not read my response to your original posting on this topic. Stand the circuit as-published against the design goals stated and see if your concerns are not already addressed by the proposed two-switch configuration. >I like the simple flow of operating the switches. However, I am not >completely comfortable without a keyswitch, which would be difficult >to include in this design. I do not like keyswitches, but there is a >clear delineation between someone being (or not) permitted to start >the aircraft if they are in possession of the key. To prevent >starting, the key would need to disconnect mag power to avoid hand >propping. The secret switch under the dash, used for auto anti-theft >is a safety of flight issue. Anyone have any good ideas how to handle >this ? What are the risks? How many folks of dishonorable behavior know how to fly YOUR airplane? Hundreds of airplanes are subjected to evil intent every year. Radios and instruments are stolen, airframes vandalized but exceedingly few airplanes are removed from their parking places. The most effective theft deterrents are the simplest. Folks who want whole airplanes are generally professional drug runners and the hauling ability of an SE lightplane is simply not in conformance with their business model. One of my favorite deterrents is used by several folks at ICT. See: http://www.aeroelectric.com/Pictures/Misc/AC_Theft_Protection.jpg THIS airplane would haul a LOT of pot . . . The whole idea of a "secret switch" doesn't consider the mind-set of folks who prey upon others. If he/she goes to work on your airplane only to find that the "puzzle" is beyond their ability solve, they're more likely to take out their frustration with a hammer to your panel or a knife to your upholstery or canopy. Thieves are a lazy lot, else they would make their living by exploiting their own productiveness as opposed to exploiting the products of others. Hence a hardened steel chain and lock is very likely to send your antagonist off to "greener" pastures. If you make the solution to the puzzle quite clear from the get-go, they're more likely to go in search of easier prey. I had a hangar renter at 1K1 ask me NOT to lock his airplane. He had to do thousands of dollars of work to repair damage to doors over the years and thieves got his radios anyhow. He correctly deduced that it was a whole lot less expensive to leave the doors unlocked and just have to replace radios. Interestingly enough, after his airplane was moved to our Podunk International Airport (See http://www.aeroelectric.com/Pictures/Misc/1K1_Spring_1989.jpg he was not victim of any more attacks against his airplane. Bob . . . ________________________________ Message 4 _____________________________________ Time: 05:58:39 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: TNC connections At 10:06 PM 1/27/2008 -0600, you wrote: > >Okay, > >I am having a hard time finding the comic book or other type simple guide to >making TNC connections. > >Is there such a creature at aeroelectic? > >I found the one for bnc >http://www.aeroelectric.com/articles/bnccrimp.pdf > >is the tnc similar? > >I ask since my Garmin 430 was converted to the new Garmin 430W and that GPS >antenna has a tnc connector. The TNC connectors I have are installed EXACTLY the same way with the same tools. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 5 _____________________________________ Time: 08:22:27 AM PST US Subject: AeroElectric-List: Alternator Problems From: "algrajek" I have a B&C 60 Amp alternator and a B&C Voltage regulator. Lately on 3 occasions, while out flying, after about 20 minutes, my alternator stops putting out( Amps go to zero, and volts start dropping). Upon landing and charging battery(to Make it home). All works well. Also notice that the volts, while cruising, while the alternator is on line, vary from 13.5to 14.9 . I have checked all the wiring and it SEEMS fine. Do I have a voltage regulator problem??? Thanks Al Grajek RV8 859-361-9460 algrajek@msn.com -------- just rv8in Read this topic online here: http://forums.matronics.com/viewtopic.php?p=160846#160846 ________________________________ Message 6 _____________________________________ Time: 11:46:53 AM PST US From: "Larry L. Tompkins, P.E." Subject: AeroElectric-List: Soliciting knowledgable comments about Eagle EMS Have any listers looked at this system? I saw it at EAA NW/Arlington 2007. I bent the ears of both the Precision Airmotive guys and Bart LaLonde at Aerosport about it. Among its appeals are excellent mixture distribution, easy starting, no return lines, self-purging for easier hot starts and seemingly a lot of redundancy designed into the system. Coming from an automotive engineering background, adjusting my R&D expectations to the reality of miniscule (by comparison) aviation sales volume has proven difficult at times for me. There just isn't enough sales volume to amortize a great deal of testing. Furthermore, I am probably a little more of a flyer than a builder, but there is nothing like an RV-7 and modern avionics available unless one builds it oneself. Although I generally am uncomfortable with the idea of being a Beta tester, the Eagle EMS has definite appeal. The system appears to be the first common rail/timed fuel injection developed for aircraft engine use. Common rail/pulse width fuel injection has been the auto industry preferred choice for at least 15 years. Precision Airmotive has had units flying in two different test beds for about 5 years, supposedly without issues. If one wishes to equip a Lycoming (clone) engine with an Eagle EMS the engine must be purchased from one of only three experimental engine suppliers, Aerosport, G&N or Penn Yann. All of these suppliers have stellar reputations. Their selection will provide some assurance of "proper installation." Perhaps this will avoid the "great debate" over whether any problems exposed are installation related, as we have seen with BMA. At any rate, if you are familiar with this system and have comments I would appreciate it if you would share them, especially if they are "failure mode analysis' type comments. Thanks, Larry Tompkins ________________________________ Message 7 _____________________________________ Time: 03:46:40 PM PST US Subject: AeroElectric-List: Firewall penetration From: "rvtach" Hi- Working on making firewall penetrations and making them fireproof. I'm using steel eyeballs for engine control cables and a stainless heater valve. I'm expecting to have a single penetration for electrical wiring and for engine sensors etc near the battery box. I like Bob's modified grab handle method for a fireproof penetration but it's larger and bulkier than I need. And it's probably not a good use of my $time$ to try to come up with a less expensive alternative to the SafeAir 1 stainless fire wall pass through system; it's only $50. But it's $50! I came across a plumbing fitting in the "swamp cooler" section of my local plumbing supply today and it just might be a $3.50 alternative. I have posted some photos at http://picasaweb.google.com/rvtach/FirewallPassthrough that show the hardware. It comes threaded internally for 1/2" NPT. I removed the threads by running a 7/8" drill through it. The whole thing fits snugly through a 1" hole and is secured by a threaded nut which would need to be secured with some thread locker. I would use firesleeve and hose clamps like Bob's grab handle or the SafeAir 1 product. There's just over 1/2" to clamp the sleeve to which is a little short but should be adequate. So, can any of you guys think of any problems with this method? Maybe I shouldn't use brass hardware against the s/s firewall? Brass melts to easily? Anything? Appreciate any help at all here. -------- Jim McChesney Tucson, AZ RV-7A Finishing Kit Read this topic online here: http://forums.matronics.com/viewtopic.php?p=160931#160931 ________________________________ Message 8 _____________________________________ Time: 04:58:12 PM PST US Subject: AeroElectric-List: Re: Firewall penetration From: "RV10 4JF" Hello, Tony Bingelis wrote an article on making pass-thru fittings. They are similar to those used on Cessnas except that they are one piece where as the Cessna fittings are two piece. They are oval in shape, SS with fire retardant material surrounding your pass-thru item. You make them out of stainless steel using sockets or pipe as the forming die. They are attached to the firewall with 2 screws. You drill a hole to fit your pass-thru item. You can make them as large or small as you like. You just have to find the right die. I will see if I can find the article and maybe I can post some pictures or a poorly drawn facsimile. BTW, in case of an engine fire, you want these fittings to provide some protection so you really need something good. JF Read this topic online here: http://forums.matronics.com/viewtopic.php?p=160942#160942 ________________________________ Message 9 _____________________________________ Time: 05:34:21 PM PST US From: "Dale Ensing" Subject: Re: AeroElectric-List: Firewall penetration Be aware of possible impact on engine sensor data if sensor leads are too close to high current (fat) wires. Dale Ensing ----- Original Message ----- From: "rvtach" Sent: Monday, January 28, 2008 6:42 PM Subject: AeroElectric-List: Firewall penetration > > Hi- > > Working on making firewall penetrations and making them fireproof. I'm > using steel eyeballs for engine control cables and a stainless heater > valve. I'm expecting to have a single penetration for electrical wiring > and for engine sensors etc near the battery box. > > I like Bob's modified grab handle method for a fireproof penetration but > it's larger and bulkier than I need. And it's probably not a good use of > my $time$ to try to come up with a less expensive alternative to the > SafeAir 1 stainless fire wall pass through system; it's only $50. But it's > $50! I came across a plumbing fitting in the "swamp cooler" section of my > local plumbing supply today and it just might be a $3.50 alternative. I > have posted some photos at > http://picasaweb.google.com/rvtach/FirewallPassthrough that show the > hardware. > > It comes threaded internally for 1/2" NPT. I removed the threads by > running a 7/8" drill through it. The whole thing fits snugly through a 1" > hole and is secured by a threaded nut which would need to be secured with > some thread locker. I would use firesleeve and hose clamps like Bob's > grab handle or the SafeAir 1 product. There's just over 1/2" to clamp the > sleeve to which is a little short but should be adequate. > > So, can any of you guys think of any problems with this method? Maybe I > shouldn't use brass hardware against the s/s firewall? Brass melts to > easily? Anything? Appreciate any help at all here. > > -------- > Jim McChesney > Tucson, AZ > RV-7A Finishing Kit > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=160931#160931 > > > ________________________________ Message 10 ____________________________________ Time: 05:41:51 PM PST US From: "Allen Fulmer" Subject: AeroElectric-List: Thumb screws for plastic hoods Having worked on PCs for the last 25 years I have learned to hate the little screws that are used to fasten db connectors to the back of computers. Fortunately, most cable manufacturers have gone to using thumb screws so a screw driver is not required. Until GRT, Trutrak, and others!! After two false starts I have finally found a supplier and the thumb screw that will fit most all the plastic db hoods provided by GRT, Trutrak, and others. You may not care BUT IF YOU DO here is the link to the part. 50 of them will cost you 12.50 plus frt. ($6.10) and tax ($1.07). Allied Electronics, Inc. Stock No. is 810-0009. Link to page follows: https://www.alliedelec.com/Search/ProductDetail.asp?SKU=810-0009&SEARCH=&MPN =B71E014276&DESC=B71E014276&R=810%2D0009&sid=479D1B001E0BE17F Allen Fulmer RV7 Wiring/Plumbing Eggenfellner Subaru E6T on firewall N808AF reserved Alexander City, AL 256-329-2001 ________________________________ Message 11 ____________________________________ Time: 06:37:30 PM PST US From: "Emrath" Subject: AeroElectric-List: Note 8 in App_ ZR11 M Bob, Instead of running the test lead from the alternator, can one run the lead from terminal #4 of the LR3C-14? do not archive Marty in Brentwood TN ________________________________ Message 12 ____________________________________ Time: 07:21:11 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Firewall penetration rvtach wrote: > > Hi- > > Working on making firewall penetrations and making them fireproof. I'm using steel eyeballs for engine control cables and a stainless heater valve. I'm expecting to have a single penetration for electrical wiring and for engine sensors etc near the battery box. > > I like Bob's modified grab handle method for a fireproof penetration but it's larger and bulkier than I need. And it's probably not a good use of my $time$ to try to come up with a less expensive alternative to the SafeAir 1 stainless fire wall pass through system; it's only $50. But it's $50! I came across a plumbing fitting in the "swamp cooler" section of my local plumbing supply today and it just might be a $3.50 alternative. I have posted some photos at http://picasaweb.google.com/rvtach/FirewallPassthrough that show the hardware. > > It comes threaded internally for 1/2" NPT. I removed the threads by running a 7/8" drill through it. The whole thing fits snugly through a 1" hole and is secured by a threaded nut which would need to be secured with some thread locker. I would use firesleeve and hose clamps like Bob's grab handle or the SafeAir 1 product. There's just over 1/2" to clamp the sleeve to which is a little short but should be adequate. > > So, can any of you guys think of any problems with this method? Maybe I shouldn't use brass hardware against the s/s firewall? Brass melts to easily? Anything? Appreciate any help at all here. > > -------- > Jim McChesney > Tucson, AZ > RV-7A Finishing Kit Is it a brass fitting? If so, it will melt at a lower temp than stainless, but so will the aluminum rivets & angles (and the copper wire going through it will, too). You might be able to find the same fitting in stainless from a food supply grade plumbing supplier. You just have to weigh risk/benefit/expense. My personal opinion is that there's much more risk from the heater penetration, even with stainless parts, than with any penetration carrying solid wires or steel cables. If you look at the air gap around the flapper valve on the heater penetration, the total area of the gap is effectively a gaping hole, compared to a wire penetration filled with wire & fire suppressing caulk. Charlie ________________________________ Message 13 ____________________________________ Time: 07:53:39 PM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Firewall penetration rvtach wrote: > So, can any of you guys think of any problems with this method? Maybe I shouldn't use brass hardware against the s/s firewall? Brass melts to easily? Anything? Appreciate any help at all here. > A big contributor to the elbow fitting's effectiveness is the elbow. The fire would have to turn a corner. You loose that with a straight through fitting. It should be fairly easy to find a stainless elbow that would do the same thing. You might have to got up to $10 to get one though 8*) ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.