After a couple of years of excellent performance, my ubitx V3 (last V3 batch with TDA2822 on socket) suddenly showed reduced receiver sensitivity and no-RF out on transmit. I have done the following tests:
- +15V on power transistor: OK.
- +12V on the main board: OK.
- total current drain on key-down: 0.6A.
- installed new firmware 1.20: OK.?
- power transistors warm-up moderately on long key-down.
- driver transistor war-up a bit on long-key-down.
- receiver works on all bands, but it has reduced sensitivity compared to previous performance.
I have no oscilloscope and no access to any lab during the present pandemia lock-down.
Any suggestion? There is anything I could chek to track the fault?
Thank you, bests
Jep, IZ0WIT
Jep