I'm wondering if I've run into this same problem. I'm using a 1/4 wave vertical with 2 tuned elevated radials.? I ran into an issue on 15, 12, and 10m SSB when I would key-down the speaker mic and the radio would start transmitting noise at full power. I can't replicate the problem on 20m or 40m.
I first had this happen on 15m with the stock mic. I then swapped that out for my headset and had the same problem.? I ended up moving to 20m for my POTA activation.
On a different occasion on 15m I started with the headset and had the problem.? I switched to the speaker mic and the problem was gone and I made 30 good QSO's on 15m.
When the problem occurs I have CMR turned on.? When I turn CMR off, the problem seems to get 95% better, although I can tell by the meter there is still some noise transmitting when I'm not talking.? (And without CMR I don't seem to get much power out on SSB).
When the problem is occurring the SWR is always low.? See picture below - the mic is keyed down and I'm not talking and there's 11w of noise being transmitted.? I don't understand why my problem would be intermittent - all with the same equipment...
Any thoughts?
Thanks & 73,
- Trevor, N6TJL
Trevor Larson - N6TJL - 3163412