---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 08/20/21: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:20 AM - Re: Com radio malfunction (Robert L. Nuckolls, III) 2. 02:29 PM - Re: Rotax 912 ULS schematics (GTH) ________________________________ Message 1 _____________________________________ Time: 07:20:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Com radio malfunction >At 06:44 PM 8/19/2021, you wrote: >Can anyone help me with this? >I bought an Apollo/UPS GX65 GPS/COM back in the 90's new from the factory. >When I finished my RV6 I installed the radio and found that the COM side >was doa. The radio display showed it powering up. >I checked all wiring except for the antenna leads and found no wiring >problems. > >I had someone repair the radio (who replaced a component but won't >tell me what the actual problem was) and am now reluctant to install >it again in case it blows up again. > >My question is: can an open or a short to ground in the antenna >lead cause the output circuits of the radio to fail? I plan to >check the antenna lead but it requires a major disassembly to get >to the antenna connection. Did the radio receive? Go ahead . . . install it and power up. See if it receives signals from local aviation facility or perhaps a hand-held. Antenna problems are almost never root cause for gross failure of components and then only transmitter components are at-risk . . . if at all. I would pressure your repair-person for a more illuminating narrative of the problem and his/her opinion as to root cause. But if they're less than 50 years old, work-bench system diagnostics are problematic. Techs understand radios pretty good. Understanding airplanes and aviation operations are something else. Information concerning those repairs belongs to you, you paid for it. But see if the radio receives first. Can you manually open the squelch (no-signal noise silencer). You should get a rushing, water-fall like noise when not receiving a signal. This is a good indication of receiver function. Try listening to a hand-held radio. If the RX is working, then go for the TX . . . it's probably just fine too. If this is a new, never been used antenna installation, an SWR check is never a bad idea whether the radio seems to be working or not. Having a good SWR reading goes more to in-flight performance later than risks to the radio. Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 2 _____________________________________ Time: 02:29:49 PM PST US Subject: Re: AeroElectric-List: Rotax 912 ULS schematics From: GTH Le 10/08/2021 18:11, Neal George a crit: > > Gentlemen - > Searching for schematics for the Rotax 912 ULS reveals a few block diagrams, but nothing with any detail. Even the maintenance and installation manuals are thin on specifics. > > Specifically, I need the pin-out for the two 6-pin connector blocks for the Ignition modules... > Hi all, Would that help http://contrails.free.fr/engine_rotax_mag_connect_en.php Best regards, Gilles http://contrails.free.fr ------------------------------------------------------------------------------------- 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.