---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 09/03/13: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:35 AM - Re: Re: Broadcast Radio Bleedover on Transceiver (Robert L. Nuckolls, III) 2. 08:26 AM - Re: Re: Over Voltage on Start Up (Robert L. Nuckolls, III) 3. 10:12 AM - Re: Over Voltage on Start Up (dbarnes) 4. 09:34 PM - Re: KT 76 Installation Manual (mariasam) ________________________________ Message 1 _____________________________________ Time: 07:35:13 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Broadcast Radio Bleedover on Transceiver At 03:18 PM 9/2/2013, you wrote: > >Seems to be coming through from the headsets. It's not near as bad >when I disconnect the co pilots headset. I wonder if an external >ground to the intercom box would help. ADDING grounds almost never helps . . . getting all the existing grounds in the RIGHT place may have a profound difference. This sounds like a classic AM demodulation condition common to many audio systems with poor ground architecture or even vulnerable audio inputs. Does it happen at other locations or just your home airport? Is there a high power AM broadcast station nearby? Bob . . . ________________________________ Message 2 _____________________________________ Time: 08:26:55 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Over Voltage on Start Up At 11:15 AM 9/2/2013, you wrote: > >Starting at the battery a #2 cable goes to the inside of the fire >wall to a plate with a field of spade connectors then through a 5/16 >inch brass bolt to the engine side of the firewall to another field >of spade connectors and also to one of the starter mounting bolts >through a large braided cable. The regulator is on the engine side >of the firewall and gets its ground from one of the spade >connectors. Originally I had the sense line of the regulator hooked >to a dedicated output from vertical power. In trying to solve this >problem I moved it to the battery positive bolt on the firewall >(through a small fuse). At first it seemed to solve the problem but >the charging voltage was too low. When I adjusted higher I was back >to the same problem. > >I am going to the hanger this pm and will try an alternate ground to >the engine block and extend wires into the plane to measure the >sense voltage and compare it to the vp displayed voltage. Very good. Your ground system appears righteous. But there's something going on that confuses or fools the regulator's otherwise clear view of the universe. Bob . . . ________________________________ Message 3 _____________________________________ Time: 10:12:32 AM PST US Subject: AeroElectric-List: Re: Over Voltage on Start Up From: "dbarnes" Bob, I tested the voltage on the sense terminal to the ground terminal on the regulator. It seemed to match the display on the vertical power. They both measured over 30 volts. The io-550 uses a direct drive alternator. I didn't have an additional ground wire on it so I added that. I took a #8 wire from the case ground to the engine block. Another plane I looked at had that so I added it. No change. Any chance the regulator is seeing too much ac from the alternator and it is confusing it? I have read in the car world that leaky, open, shorted diodes sometimes cause strange problems. Thanks, Dan Barnes Read this topic online here: http://forums.matronics.com/viewtopic.php?p=407985#407985 ________________________________ Message 4 _____________________________________ Time: 09:34:09 PM PST US Subject: AeroElectric-List: Re: KT 76 Installation Manual From: "mariasam" Seems to be coming through from the headsets. It's not near as bad when I disconnect the co pilots headset. I wonder if an external ground to the intercom box would help. :P [Laughing] -------- maria Read this topic online here: http://forums.matronics.com/viewtopic.php?p=407997#407997 ------------------------------------------------------------------------------------- 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.