skeptic36 Posted January 1, 2016 Share Posted January 1, 2016 Hi all, I have an MGL V6 radio installed in my trike and I use it in conjunction with flycom integrated helmet/ headsets . All works really well except if I try to transmit with the pax headset plugged in, then it sounds like I'm talking down a pipe and is almost unreadable to other stations, if I pull the plug on the pax and then transmit, back to 5/5. While researching what could be the problem, I read that if you transmit with a poor or damaged aerial some of the power will go back to the radio and may damage it. A while ago ( when I think about it, it would be about the time this started) I had the joint in my coax come apart where the mast is connected to the wing, and I know I tried to transmit when in this condition ( I didn't know it had come apart). My questions are : Could the damage this can cause, be the reason for the symptom I have? If so, is it repairable Thanks Regards Bill Link to comment Share on other sites More sharing options...
microman Posted January 1, 2016 Share Posted January 1, 2016 I have an Icom 200 in my Alpi with a Skycom intercom fitted and guess what - exactly the same problem as skeptic36 - huge background noise on transmit (not all the time) - unplug the pax headset from the jack and hey presto - the noise has gone - can anyone throw any light on this problem? Radios!!!!!! I never seem to have one that works well - perhaps because I install them myself and I dont really know what I'm doing! Link to comment Share on other sites More sharing options...
Birdseye Posted January 1, 2016 Share Posted January 1, 2016 Sounds as though when you transmit the pax headset mike is also going live. If its a dual jack headset arrangement, leave the pax mike plug out and see if the problem still exists. Link to comment Share on other sites More sharing options...
jakej Posted January 1, 2016 Share Posted January 1, 2016 Pax mic jack wired incorrectly, pm me a photo of it or send to 0412 624 723 Link to comment Share on other sites More sharing options...
skeptic36 Posted January 1, 2016 Author Share Posted January 1, 2016 Hi Jakej, Thanks for the reply. I doubt that could be the problem in my installation, because it is a relatively new trike and it worked fine when I got it and that part has not been touched. Link to comment Share on other sites More sharing options...
jakej Posted January 2, 2016 Share Posted January 2, 2016 Bill Your comment - " if I pull the plug on the pax and then transmit, back to 5/5." indicates to me the transmitter is ok. Did you swap headsets & try the same test, with & without pax side plugged in ? If the problem has shifted to Pilot position then fault is with the headset, if not then it has to do with the pax wiring, mic jack/Ptt switch. Let me know how it goes - call me if you want (don't have to identify yourself) Link to comment Share on other sites More sharing options...
skeptic36 Posted January 2, 2016 Author Share Posted January 2, 2016 Thanks Jake, I'll give that a try. Link to comment Share on other sites More sharing options...
Virago Posted January 2, 2016 Share Posted January 2, 2016 Hi skeptic36, It would seem your two headset mics are wired simply in parallel. Sometimes, one mic will load the other resulting in degraded performance. If possible, use a pair of relays controlled by each PTT switch so that the other mic audio line is opened when the pilot is TXing and vice versa when the PAX is TXing. John (retired avionics LAME). Link to comment Share on other sites More sharing options...
skeptic36 Posted January 7, 2016 Author Share Posted January 7, 2016 The MGL guy got back to me today. There is a setting in the radio to "join" or "seperate" the two headsets in the PTT . He said seperate them. I've just been and had a look, and sure enough it was set to join. I have changed it and hope to fly with a pax in the morning. I will report the results tomorrow , but it looks promising. Buggered if I know how it got changed, because, as I said it used to work fine and it is several steps through the menu which I have never even had the need to open before. Regards Bill Link to comment Share on other sites More sharing options...
Virago Posted January 7, 2016 Share Posted January 7, 2016 That's great news Bill. I've found the MGL people to be very helpful and that's why my project will have MGL gear. John Link to comment Share on other sites More sharing options...
Virago Posted January 7, 2016 Share Posted January 7, 2016 Bill , have you changed a headset, or had a mic changed on one of your headsets. If the two mics are perfectly matched, there's usually no problem (except both mics will be picking up cockpit noise). If there is an imbalance between the mics, one will "load" the other and you will have problems. MGL's suggestion should do the trick. Good luck! John Link to comment Share on other sites More sharing options...
skeptic36 Posted January 9, 2016 Author Share Posted January 9, 2016 Hi John, there has been no changes to anything to my knowledge, but something must have changed accidentally because it's three steps through the menu to change the PTT setting , and I certainly didn't do that. I tested it this evening with the new setting and it worked perfectly. Regards Bill Link to comment Share on other sites More sharing options...
Virago Posted January 9, 2016 Share Posted January 9, 2016 Great outcome Bill. Well done! Link to comment Share on other sites More sharing options...
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