Cobra 29LX receives but won’t transmit!

Discussion in 'CB Radio Forum' started by Midnightrider909, Nov 11, 2021.

  1. Midnightrider909

    Midnightrider909 Road Train Member

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    I bought a new microphone thinking that might be the issue but still nothing. I ran through the owner’s manual and it is calibrated so what cohld be the problem? I have a twin antenna setup on my Volvo 780.
     
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  3. Don379

    Don379 Heavy Load Member

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    so the transmit light isnt lighting up and needle not moving?
     
  4. Midnightrider909

    Midnightrider909 Road Train Member

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  5. Midnightrider909

    Midnightrider909 Road Train Member

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    This is what the display looks like when I transmit. 5F6D296E-1AD9-41F5-92EA-015E05D9853B.jpeg
     
  6. Night Stalker10

    Night Stalker10 Road Train Member

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    I assume it's been working and then quit? Not sure what you mean by calibrated, unless your referring to using the worthless internal SWR meter. Do you have an external SWR meter to see if it has RF output? These cobras are known to have lots of cold solder joint problems. That's what I expect is going on. More info would help.
     
  7. Night Stalker10

    Night Stalker10 Road Train Member

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    Okay after a closer look, I see your in the SWR mode, and like usual for these radios, it shows around 1.2. You still need an external swr or power meter to verify if it has RF output. Unless by no transmit you mean no audio.
     
  8. Midnightrider909

    Midnightrider909 Road Train Member

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    We have a handheld CB and when I press the transmit button in the truck it transmits static and no sound.
     
  9. Night Stalker10

    Night Stalker10 Road Train Member

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    Okay, have you tried the PA to see if you get audio through the internal speaker? Be sure and turn the mic gain way down before you key the Mic. Then as you talk, slowly bring the mic gain up and hopefully you will hear yourself talk. If this works , then the mic and audio section is good. It's still possible there's a cold solder joint somewhere or the TX final is bad. Tnx for the picture, that sure helps to see what it's doing.

    I'm not sure the TX final is bad just yet. It sounds like from your first post that you were able to calibrate the internal swr meter, which sounds like you are getting RF power out. But how much we don't know without a power meter.
     
    Last edited: Nov 12, 2021
    Midnightrider909 Thanks this.
  10. flood

    flood Road Train Member

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    To test/check the mic turn the talk back UP, key up the mic and talk, if you don't hear it the mic or 1 of the pins in the plug is bad
     
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