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Noise in transmitted audio. Noise in microphone.

Rick WN2C
Rick WN2C Member ✭✭
in FLEX-8000 Signature Series

I get noise in my transmit audio when running 100 watts and higher power. I usually run VOX and it will keep the transmitter keyed until I shut off the VOX. I purchased on 5/19/2026 and have yet to use the radio on any band except 10 meters. I replaced a 6400M with this radio and the only change that was made was the radio. All peripherals mic, tuner, amp, are the same. I believe there is a problem with the radio. I have used a different XLR cable to no avail. I tried the FHM3 hand mic and the audio is weak. I use a Heil PR 781 and have heard noise coming the Mic even though the Bias is turned off, which is why the VOX is held open.

Any thoughts or suggestions?

Answers

  • Arnold Goldman
    Arnold Goldman Member ✭✭

    i had a problem with the 8600M had to put RF chokes on the mic, tgxl and pgxl cables; look at palomar enfineers they sell RF packages for them;

  • Rick N0VT
    Rick N0VT Member ✭✭✭
    edited May 31

    I've made it a rule to first suspect and rule out RFI anytime something goes wonky when transmitting.

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    I think we need some more details.

    • can you describe the noise?
    • Does the problem go away at lower power? If so, it is an RFI issue.
    • What are you using for an antenna? Is it an EFHW? Is it near the radio? If EFHW, you will need chokes (Mix 43) on both ends of the feedline to keep the RF off the feedline and radio. If an EFHW, I would very highly recommend that you add a couterpoise to the to the antenna to move the RF off the feedline
    • Do you have Noise on your transmit audio if you do not use a MIC but use PC audio?

    Take a moment to answer these and it will help to narrow things down.

  • John KB4DU
    John KB4DU Member ✭✭✭✭

    What Rick said.

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