(tr)uSDX Forum

When i push the ptt button on ssb on my hi bands kit and only on 15meter the unit transmit. I can
still make qso on 15m but i do not know where to look for this problem.

I also see this on one of the two high band boards I have built. I also have this issue on all 3 classic boards I have built but only on 20 meters . In all cases if I use an external microphone the issue goes away. So this looks like a problem for both the high band on 15 meters and the classic band on 20 meters. I assume the on board mic is getting RF into it?

Any thought on how to prevent this? For now my fix is to use an external mic but on hikes I’d prefer not to take any extra items like a mic.

73 Bill NG1P

@ve2rn Can you clarify the problem you're seeing? Your description is a little ambiguous, and I'm having trouble parsing what you've written.

Is it that you can transmit on 15m only and are unable to transmit on the other bands?

The issue is when pushing the PTT button while in LSB or USB the radio is producing about 2 watts out with out speaking into the mic. It just goes into an oscillation state. I have seen this behavior on the high band board on 15 meters and the classic board on 20 meters (all 3 that I have built). When using an external microphone the issue does not happen. It only happen using the the on board mic/PTT button