Tramsmit problems

Discussion in 'Instruments / Avionics / Electrical System' started by berniematic, May 26, 2017.

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  1. May 26, 2017 #1

    berniematic

    berniematic

    berniematic

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    I don't know if you can help with this in the forum but here goes;
    My plane is a Wittman Buttercup with the first series Lyc. 0-235, probably never intended to be in front of a radio. P leads are shielded except for a few inches were they connect to the mags. I have an wire external antenna.
    I had been using handheld radio going thru outside antenna. Seemed to work but but a pain to handle. So - I installed an old Collins Com radio on top of the dash and wired it all up with PTT and headphones. Its a better setup but - receive is loud and clear, Xmit light lights and there is garbled, staticy transmission and people can't understand me. I just re-routed the shielded antenna lead away from the inside firewall but no improvement. Suggestions for what to try next?? Thank you.
     
  2. May 26, 2017 #2

    BJC

    BJC

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  3. May 26, 2017 #3

    bmcj

    bmcj

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    The transmit problem is obviously in the spelling.

    (Sorry, I couldn't resist... should have, but didn't.)
     
  4. May 27, 2017 #4

    berniematic

    berniematic

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    Hmmm - Bad pre-post inspection. Thanks, I'll check the other site.
     
  5. May 27, 2017 #5

    TFF

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    How is the ground plane and is the coax the right length?
     
  6. May 27, 2017 #6

    don january

    don january

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    sorry no idea
     
  7. May 27, 2017 #7

    Aerowerx

    Aerowerx

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    Does it work with the engine off?

    Are you sure that the transmitter is functioning properly?
     
  8. May 28, 2017 #8

    berniematic

    berniematic

    berniematic

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    Ground plane - Antenna is mounted under cabin in the forward 1/3 of an aluminum panel, painted on the outside. This seemed to work with the handheld unit.
    Coax Length - I was unaware this was critical. It a little long, but not much to get from the top of panel to the floor.
    Work on the ground - Well - yeah. I tried it from one end of the runway to the other (2000 ft) and it was OK, not great, I attributed that to my being close to the ground and under the plane with the antenna.
    Xmit function - All I have to go on is that ground test and a response from a tower from 5 miles out when I first installed it. They reported readable with static. Since then (about 5 flights) another different tower and another plane 2 miles away reported static and unreadable.

    The only radio wire I have shielded is the coax. Because all the other wires (mic, audio, power, PTT) attach to the back close to each other with no shielding, I assumed none was needed. And they are wrapped together. Is this a problem? Thanks again.
     

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