---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 06/02/10: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:33 AM - Re: Re: Long and short hot feeders (Robert L. Nuckolls, III) 2. 08:42 AM - Joining RG58 to RG400 (Greg Reid) 3. 08:53 AM - Re: Joining RG58 to RG400 (Robert L. Nuckolls, III) 4. 09:13 AM - test (mike gamble) 5. 09:40 AM - Re: Speaking of soldering (Robert L. Nuckolls, III) 6. 09:54 AM - Found the Cause of My Problems (John Markey) 7. 10:44 AM - Radio Noise (Jim Thorne) 8. 12:50 PM - Re: Joining RG58 to RG400 () 9. 12:56 PM - Re: Radio Noise (David & Elaine Lamphere) 10. 01:54 PM - Re: Radio Noise (Robert L. Nuckolls, III) 11. 01:58 PM - Re: Found the Cause of My Problems (Robert L. Nuckolls, III) 12. 02:00 PM - Amp shunt mount-cockpit or outside? (CardinalNSB@aol.com) 13. 02:25 PM - Amp shunt mount-cockpit or outside? (BobsV35B@aol.com) ________________________________ Message 1 _____________________________________ Time: 08:33:30 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Long and short hot feeders At 12:43 AM 6/2/2010, you wrote: Aargh! I hate arguing with common sense and good design when I've spent all that time making that cute little panel. But your reasoning is hard to refute. Honestly I got so caught up in making this cool fuse panel and getting 30 fuses in a tight pattern that I overlooked the fact that I was going to have a whole nest of hot wires to deal with. Just have to get used to not being able to see my fuses and comfort myself with fewer parts count and fewer constructed joints. And ditto on the battery bus. It's moving back to the battery. Again thanks for taking the time to explain all this. I makes it a little easier to throw that fuse panel into the trash. You're not alone. EVERY finely tuned recipe for success was preceded by many if not thousands of experiments that were discarded. Thomas Edison was often referred to as the "master experimenter" in recognition of his patience and persistence in the conduct of his craft. Charles Kettering, ditto. I cannot begin to deduce the magnitude of my own efforts that that ultimately went into the trash . . . the reason being that those experiences were discarded both physically and intellectually. But when the effort was successful, the work product went into useful service and the recipe for success went into the intellectual archives for future reference. I recall visiting an estate sale about 20 years ago that included a lot of goodies from a ham radio operator that had departed this earthly plane. While digging through a pile of stuff, I was startled to see a familiar device. It was a vacuum tube electronic code keyer that I built for another ham perhaps 25 years earlier . . . I don't know how many times it changed hands but it was still functional. Further, I could still draw a schematic for the thing. Good education is NEVER inexpensive in terms of $time$ and slips to schedule. But it seems to me that the most "expensive" lessons are best retained. By having this discussion on the List, we're reducing the investment necessary for others to benefit from simple-ideas that go into their own exploitation of the same recipe for success. If it's any consolation, your loss contributes to the gains of others . . . but only if it's shared. I've often remarked to publishers of my articles that they solicit articles on failures too. I always get a reaction of surprise and perhaps dismay. I then explain that it's often more useful to know what does not work as things that do work. It's a prophylactic against repeating the same failure over and over again. Keep at it my friend and thanks for participating. Bob . . . ________________________________ Message 2 _____________________________________ Time: 08:42:10 AM PST US From: "Greg Reid" Subject: AeroElectric-List: Joining RG58 to RG400 I constructed my empennage in 2003 (hard to believe it's been that long!) from fiberglass with four internal RST copper foil antenna (COM1, COM2, VOR, ELT) plus a MB antenna running down the fiberglass dorsal fin. I used Radio Shack RG58 coax at the time 'coz it was conveniently available as I was closing out the empennage -- following the RST directions for baluns on the connection between foil and coax. I used 40-ish foot lengths of the RG58 from each antenna (coiled up for now) to leave me plenty to reach the back of the instrument panel without any break. A year-ish later, I learned via this forum of the much lighter, slimmer, and more elegant RG400 coax. I bought five 15-foot lengths of RG400, with male BNCs attached on each end, through a "bulk purchase" offered in this forum in 2004 (hard to believe it's been that long!). So now, as I'm finally getting around to routing my wires and coax forward, I'd like to cut off each of the RG58's just behind the rear seats (where I can still easily reach them) and connect to the RG400's for the remaining 14-ish foot trip forward to the rear of the panel. Should I install a female BNC connector on the RG58 for connecting to the mail BNC on the RG400, or can I directly splice the RG58 to the RG400 ... while doing my best to maintain a continuous outer shielding across the transition? Or would I be asking for trouble (e.g. mismatched impedance reflections) by mixing RG58 with RG400 ... so just continue with the RG58 all the way forward? Thanks, Greg ________________________________ Message 3 _____________________________________ Time: 08:53:00 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Joining RG58 to RG400 > >Or would I be asking for trouble (e.g. mismatched impedance reflections) by >mixing RG58 with RG400 ... so just continue with the RG58 all the way The performance difference between the two materials is slight. Your VHF radios are not going to work better in any observable way. I think the drive is going to be parts count. The act of splicing the two feeders together adds a handful of parts with the additional risk of future failure. If it's not practical to replace the 58 with contiguous lengths of 400, I think I'd opt to leave the 58 in place. But a cable male/female joint would be quite acceptable too. http://www.aeroelectric.com/Pictures/Connectors/Coax/BNC_Cable_Female_1.jpg http://www.aeroelectric.com/Pictures/Connectors/Coax/BNC_Cable_Male.jpg Bob . . . ________________________________ Message 4 _____________________________________ Time: 09:13:26 AM PST US From: "mike gamble" Subject: AeroElectric-List: test ________________________________ Message 5 _____________________________________ Time: 09:40:05 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Speaking of soldering At 08:10 AM 6/2/2010, you wrote: >Hello Bob, > >What was the product you purchased? Sorry, here's one of several offerings for the tool on Ebay. http://tinyurl.com/278pb3w Bill makes an important point. This critter is an ignition hazard so be cognizant of the working environment. Combustible liquids with low vapor pressures are especially hazardous. I keep cans of "carburetor cleaner" (really a kind of lacquer thinner in a aerosol can) around for little shots of de-greasing agent. It avoids having spillable containers of the stuff around and limits the amount and duration of combustible mix in the air. Also, you DO want to check for effective shut-off for gas flow. I've had a few tools over the years that would leak out in the toolbox . . . but this is rare. You can charge your new tool and just let it set for a goodly amount of time and make sure it's tight. You can perhaps smell gas flows that are too small to hear. Bob . . . ________________________________ Message 6 _____________________________________ Time: 09:54:07 AM PST US From: John Markey Subject: AeroElectric-List: Found the Cause of My Problems - I recently have been fighting a whole bunch of electrical gremlins: 1. Booster pump would work intermittently; 2. Engine gages would or wouldn't function [GRT EIS]; 3. Starter would not engage - bang it and it would fire right up! 4. Lost charge on new battery [replaced as a preventive measure after 4 yea rs] --- but it mesured @ 12.4 volts when it was "dead". - I began with the multimeter this Saturday with 2 other pilots [this is not necessarily a good thing - the help, that is]. All circuits tested hot when they should be hot, but everything was dead! - Hmmm.... after thinkng this little tidbit over, I recalled an old post year s back on a similar issue. A contacter or switch making contact, but at high resis tance under load, but it "looks OK" under low or no load - e.g., with a multimeter using a 1.5 volt cell. - Sitting under the white plastic bootie that covered it, I found the lock nu t loose that attached the main power lead OUT from the main power solenoid. This nut had somehow come loose over the years, and it was severely pitted with metal from the arching - probably every time I engaged the starter. - Very scary, but hey, I'm VFR. - Lesson Learned: check each and every nut at Annual, especially under those connector covers that sit in hard-to-reach locations. - John Deep peace of the Light of the World to you. ------------------------- ------------------------ -- A Gaelic Blessing =0A=0A=0A ________________________________ Message 7 _____________________________________ Time: 10:44:42 AM PST US From: "Jim Thorne" Subject: AeroElectric-List: Radio Noise Here is a tough one that maybe some of you guys can point me in the right direction to look. Set up is: RV-7A with an SL-30, Bob Archer antenna in left wingtip, with PTT on stick also FWIW I have a P-Mag and E-mag. Radio is excellent on ground in both transmit and receive, reception in air is OK however when I press the PTT the noise is horrible with static and breaking up. This has been a consistent condition. Attempts to correct the problem have been: checking antenna installation in wingtip, everything seems fine, Checking connectors where stick PTT plugs into the system, the PTT pin may not have been fully seated, it is now, trying different headsets. Nothing has solved the problem to date. I have been working with the tower on this flying the same circuit and when I contact them it is always somewhere between almost NORDO to just generally poor communications. When I'm back on the ground everything is just fine again. Ideas, directions or suggestions? Jim Thorne RV-7A CHD About 12 Hours now. ________________________________ Message 8 _____________________________________ Time: 12:50:21 PM PST US Subject: RE: AeroElectric-List: Joining RG58 to RG400 From: Greg, Welcome to 2010 :) Hey, time to get building. I did the same on my NAV (joined it with a female) and found no difference in quality. They are all rated at 50 ohms. Truthfully, I've never been able to justify the added cost of the pure RG400 plumbing over the RG58 plumbing. I've also got 142 plumbing. The RG58 radios work just as well as those with the $$ wire. Of course we could also open a thesis on location, type and quality of antenna installations. Oh boy. The more technically wire adept will differ but if you sat in my plane you'd never know the difference. Glenn -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Greg Reid Sent: Wednesday, June 02, 2010 11:25 AM Subject: AeroElectric-List: Joining RG58 to RG400 I constructed my empennage in 2003 (hard to believe it's been that long!) from fiberglass with four internal RST copper foil antenna (COM1, COM2, VOR, ELT) plus a MB antenna running down the fiberglass dorsal fin. I used Radio Shack RG58 coax at the time 'coz it was conveniently available as I was closing out the empennage -- following the RST directions for baluns on the connection between foil and coax. I used 40-ish foot lengths of the RG58 from each antenna (coiled up for now) to leave me plenty to reach the back of the instrument panel without any break. A year-ish later, I learned via this forum of the much lighter, slimmer, and more elegant RG400 coax. I bought five 15-foot lengths of RG400, with male BNCs attached on each end, through a "bulk purchase" offered in this forum in 2004 (hard to believe it's been that long!). So now, as I'm finally getting around to routing my wires and coax forward, I'd like to cut off each of the RG58's just behind the rear seats (where I can still easily reach them) and connect to the RG400's for the remaining 14-ish foot trip forward to the rear of the panel. Should I install a female BNC connector on the RG58 for connecting to the mail BNC on the RG400, or can I directly splice the RG58 to the RG400 ... while doing my best to maintain a continuous outer shielding across the transition? Or would I be asking for trouble (e.g. mismatched impedance reflections) by mixing RG58 with RG400 ... so just continue with the RG58 all the way forward? Thanks, Greg ________________________________ Message 9 _____________________________________ Time: 12:56:24 PM PST US From: "David & Elaine Lamphere" Subject: Re: AeroElectric-List: Radio Noise Jim, You didn't say what you were using for a headset and intercom. If the headset's mike is too sensitive, and your cockpit (while flying) is so noisy that it overwhelms the intercom (or radio) input - this could cause your symptoms. If there's a second headphone connected but left in place (not used), this will also cause a great deal of noise troubles. Try and find someone to loan you a different headset (preferrably one that has active noise cancelling) and see what that does... Just a suggestion... Dave L. Wittman Tailwind (60hrs) (quite a noisy cockpit: PS1000II intercom and Lightspeed Zulu + 15XL headsets work OK) ----- Original Message ----- From: Jim Thorne To: aeroelectric-list@matronics.com Sent: Wednesday, June 02, 2010 1:42 PM Subject: AeroElectric-List: Radio Noise Here is a tough one that maybe some of you guys can point me in the right direction to look. Set up is: RV-7A with an SL-30, Bob Archer antenna in left wingtip, with PTT on stick also FWIW I have a P-Mag and E-mag. Radio is excellent on ground in both transmit and receive, reception in air is OK however when I press the PTT the noise is horrible with static and breaking up. This has been a consistent condition. Attempts to correct the problem have been: checking antenna installation in wingtip, everything seems fine, Checking connectors where stick PTT plugs into the system, the PTT pin may not have been fully seated, it is now, trying different headsets. Nothing has solved the problem to date. I have been working with the tower on this flying the same circuit and when I contact them it is always somewhere between almost NORDO to just generally poor communications. When I'm back on the ground everything is just fine again. Ideas, directions or suggestions? Jim Thorne RV-7A CHD About 12 Hours now. ________________________________ Message 10 ____________________________________ Time: 01:54:29 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Radio Noise At 12:42 PM 6/2/2010, you wrote: >Here is a tough one that maybe some of you guys can point me in the >right direction to look. Set up is: RV-7A with an SL-30, Bob Archer >antenna in left wingtip, with PTT on stick also FWIW I have a P-Mag >and E-mag. Radio is excellent on ground in both transmit and >receive, reception in air is OK however when I press the PTT the >noise is horrible with static and breaking up. "Static" implies a condition like the noises heard as a result of lightning strikes, spark plugs firing and other electrical conditions common to the generation of sparks. "Breaking up" suggests that the desired signal (in this case your voice) is there sometimes and absent for other times. Does your microphone/headset combo include intercom operations . . . or can it include such operations? Are the noises present in intercom mode as well as radio transmit? Try a plain ol' hand-held microphone in the place of your headset microphone. Is the noise condition any different? As others have suggested, the condition you describe is MOST likely a head set problem wherein the noise cancelling characteristics of the microphone are poor to nil. While airborne, hit the PTT button on the stick with the microphone connector unplugged. Does the noise go away? Bob . . . ________________________________ Message 11 ____________________________________ Time: 01:58:57 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Found the Cause of My Problems > >Lesson Learned: check each and every nut at Annual, especially under those >connector covers that sit in hard-to-reach locations. Your story is not uncommon. Loosening hardware is one of the higher-order risks. Nylon or fiber insert lock nuts are a fair bet. Also, consider a mild thread-locker designed for maintenance removal. This is especially useful on contactors with coarse threads more likely to loosen up under vibration of heavy lead wires attached. This is another advantage of welding cable as a fat-wire material . . . the stuff is so flexible that its ability to transmit torsional vibration to the stud is far lower than for "aircraft wire". Bob . . . ________________________________ Message 12 ____________________________________ Time: 02:00:42 PM PST US From: CardinalNSB@aol.com Subject: AeroElectric-List: Amp shunt mount-cockpit or outside? Thank you all. The reason for my change is that the factory charging lead starts at the alternator on the co-pilot front, goes back to the firewall, crosses the firewall to the far left, enters the cockpit through the firewall on pilot's side, goes all the way over to the circuit breaker next to the co-pilot side hull (buss intersects here), then goes all the way back across to the pilot's side for the internally shunted Cessna amp gauge, then out the same firewall hole to the main battery cable. No, really, it does. 3 funs of fat wires running all the way from left to right, 2 runs inside the cockpit. This is part of my general clean up of 45 years of old wiring, etc. My ap is ok with a minor change of simply going from the alternator into the cockpit to the cb on the far co-pilot side, then back out the firewall and then over to intersect the main battery cable. Using the externally shunted ammeter makes the above possible, also gives voltage and a settable warnings. EI's instrument is certified as a primary replacement for the factory gauge, using either the internal or external shunt. So last question-should the shunt be mounted in the cockpit or on the firewall side? Skip S. ________________________________ Message 13 ____________________________________ Time: 02:25:29 PM PST US From: BobsV35B@aol.com Subject: AeroElectric-List: Amp shunt mount-cockpit or outside? Good Afternoon Skip, Since you have asked. I would Definitely go with the external shunt mounted in the engine compartment and on the firewall. I would also place a fuse block on the firewall as close to the shunt as possible for the leads to the shunt from the cockpit instrument. That is the way Beechcraft mounted the shunt for the factory gauge on my 1978 V35B. When I added the VA-1 to monitor the primary and standby alternators I placed the new shunts right alongside the factory shunt and placed the new fuse blocks alongside the factory fuse block. I think you will find that one of the wiring options shown by EI suggests what I have described. Works great and keeps all those fat wires out of the cockpit! Happy Skies, Old Bob In a message dated 6/2/2010 4:01:31 P.M. Central Daylight Time, CardinalNSB@aol.com writes: Thank you all. The reason for my change is that the factory charging lead starts at the alternator on the co-pilot front, goes back to the firewall, crosses the firewall to the far left, enters the cockpit through the firewall on pilot's side, goes all the way over to the circuit breaker next to the co-pilot side hull (buss intersects here), then goes all the way back across to the pilot's side for the internally shunted Cessna amp gauge, then out the same firewall hole to the main battery cable. No, really, it does. 3 runs of fat wires running all the way from left to right, 2 runs inside the cockpit. This is part of my general clean up of 45 years of old wiring, etc. My ap is ok with a minor change of simply going from the alternator into the cockpit to the cb on the far co-pilot side, then back out the firewall and then over to intersect the main battery cable. Using the externally shunted ammeter makes the above possible, also gives voltage and a settable warnings. EI's instrument is certified as a primary replacement for the factory gauge, using either the internal or external shunt. So last question-should the shunt be mounted in the cockpit or on the firewall side? Skip S. 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