---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 03/06/17: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:21 AM - Troubleshooting Assistance Radio (Jim Heekin) 2. 11:52 AM - Re: Troubleshooting Assistance Radio (Stein Bruch) ________________________________ Message 1 _____________________________________ Time: 11:21:13 AM PST US Subject: AeroElectric-List: Troubleshooting Assistance Radio From: "Jim Heekin" Folks, I would really appreciate some advice I've been wandering in the wilderness for a couple of days now. Original condition of the radio stack: KMA-24 audio panel, two KX-155s (comm 1 and 2), NAT AA80-001 intercom, Narco 150 transponder and TCI digitizer. The mission was to replace the Narco 150 with an NGT-9000 for compliance with the ADS-B mandate. Because of the NGTs enhanced display, I positioned it at the top of the radio stack just below the KMA-24 audio panel. The two KX-155s were moved down a notch to a position just below the NGT. In the process I took the opportunity to remove a significant amount of orphan wire that remained after previous avionics upgrades, both behind the panel and in the floor. The good news the NGT checks out and works as advertised. The more challenging news I've lost the ability to transmit voice modulation from the KX-155s. The intercom functions properly from all four positions in the aircraft using various headsets. The radios transmit when the buttons on the yokes are pushed. The intercom indicates transmission (light shows green) and a signal is getting out (I can key the airports weather advisory report with four clicks). But, no voice transmission results when the transmit button is keyed and there is no sidetone in the headsets. The standby mic wired into the intercom system for emergency power outage does not seem to function for voice transmission either. Initially, I thought I may have disturbed the connections between the intercom and the audio panel in the process of removing and lowering the KX-155s. I removed both the audio panel and the intercom and put a tracer on the logical wires (radio mic hi, radio keyline and radio audio hi in the intercom harness). All indicated continuity from the intercom harness into the audio panel connector. I would greatly appreciate any suggestions on next steps that I might check or try. I can post the pin configurations for each appliance if that would be helpful to the analysis. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=466943#466943 ________________________________ Message 2 _____________________________________ Time: 11:52:15 AM PST US From: "Stein Bruch" Subject: RE: AeroElectric-List: Troubleshooting Assistance Radio If the TX lights come on the KX's and your intercom is working great between headsets just sitting there, it almost has to be the Mic Audio Hi wires for the KX's (either between the radios and the KMA or between the KMA and the NAT). I'd look between the NAT and the KMA first... Cheers, Stein -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jim Heekin Sent: Monday, March 06, 2017 1:18 PM Subject: AeroElectric-List: Troubleshooting Assistance Radio --> Folks, I would really appreciate some advice I've been wandering in the wilderness for a couple of days now. Original condition of the radio stack: KMA-24 audio panel, two KX-155s (comm 1 and 2), NAT AA80-001 intercom, Narco 150 transponder and TCI digitizer. The mission was to replace the Narco 150 with an NGT-9000 for compliance with the ADS-B mandate. Because of the NGTs enhanced display, I positioned it at the top of the radio stack just below the KMA-24 audio panel. The two KX-155s were moved down a notch to a position just below the NGT. In the process I took the opportunity to remove a significant amount of orphan wire that remained after previous avionics upgrades, both behind the panel and in the floor. The good news the NGT checks out and works as advertised. The more challenging news I've lost the ability to transmit voice modulation from the KX-155s. The intercom functions properly from all four positions in the aircraft using various headsets. The radios transmit when the buttons on the yokes are pushed. The intercom indicates transmission (light shows green) and a signal is getting out (I can key the airports weather advisory report with four clicks). But, no voice transmission results when the transmit button is keyed and there is no sidetone in the headsets. The standby mic wired into the intercom system for emergency power outage does not seem to function for voice transmission either. Initially, I thought I may have disturbed the connections between the intercom and the audio panel in the process of removing and lowering the KX-155s. I removed both the audio panel and the intercom and put a tracer on the logical wires (radio mic hi, radio keyline and radio audio hi in the intercom harness). All indicated continuity from the intercom harness into the audio panel connector. I would greatly appreciate any suggestions on next steps that I might check or try. I can post the pin configurations for each appliance if that would be helpful to the analysis. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=466943#466943 ------------------------------------------------------------------------------------- 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.