After replacing the Final PS transistor as discussed in this thread, I thought the issue had been resolved.
But something weird happened this morning as I used the iambic keyer to call CQ, it appeared the box got ‘stuck’ on transmit, I saw the SWR climb to about 1:3.
I quickly switched off the device and tried again.
When it got stuck in transmit, I ‘jiggled’ the keyer by sending couple random dits and dahs and the transmit stopped.
I tried again. This time when it got stuck I looked at everything I could to gather as much dat as possible.:
- SWR rises to 1:3
- LCD does not show the ‘P’ indicator, but ‘S’ with a full receive signal.
- Audio turned to a bit of a squealing distortion
- Smoke came out of the unit and the screw that affixes the Final PA Transistor to the housing was very hot to the touch.
- I opened the housing and verified visually that the transistor was damaged
So I replaced the transistor again, and again have full power on transmit, but am seeing it get stuck again and the SWR climbing with the squealing sound.
I switched the unit off and am posting this now to see if there are any ideas out there as to what I should look at as the culprit here.
As always, any feedback and input is highly appreciated.