Re: QMX Receive suddenly stop working
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Howard ,
There is some additional info that you can provide to help steer the suggestions in the right direction.
What band model QMX? (HB or LB) are you using? What version level? Was it factory made or did you assemble it? Does it still transmit and produce proper power levels?
There are several possibilities that could result in a deaf RX. Loss of an intermittent solder joint especially at the band switch inductor is one. Failure of the band switch mux chip is also a possibility. Failure of the T/R switch transistor will also deny signal passage, but TX power would likely be affected, too.
JZ KJ4A?
My QMX was working fine and I made couple of QSO via FT8. However I noticed the receiver stop working:
1. I can still hear some strong signals.
2. When I plugin my attena, the S-meter in WSJT-x is not changed. keep in less than 10db. when it was working, it should be around 30-40db.
3. I use rs232 console to test RF filter, it show very large att.
I verified all bands are like this. Compare to operation guide, the Y-axis is significant small (-30db).
Any suggestions what I should check?
-Howard?
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