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QCX+ 20M Lost sensitivity


Bruce KS4V
 

I was listening to my QCX+ yesterday on 20 meters and all of a sudden I noticed my received signals dropped off considerably.  I can only copy a few of the loudest signals, which are very weak on my QCX+.
The receiver portion had been working quite well up to that point.  I  went through the alignment procedure again and noticed that as I turn C1 to peak the bandpass filter, I do not see but a one or two bar difference in the entire range of C1.  Transmitter is putting about 2.4 watts from a 12 v power source.  I will try removing a turn off L3 to boost the power after I get the receiver straightened out.
I am looking for ideas where to start with very limited test equipment.  Thanks, Bruce  KS4V


@CurtisM
 

Bruce

My guess is you lost a solder connection somewhere. If you check your alignment and its no longer nulled, most likely its within audio, okay easy guess since nearly all of receiver is audio.

Just turn on the builtin test signal. Check peaking of  the trimmer capacitor. Leaving the test source on, poke around with your finger and see if your audio recovers when you touch the now open connection. This is how I found the issue with my first qcx. Oh I did this once on my valve receiver, except using a stick.

73 curt


Alan G4ZFQ
 

My guess is you lost a solder connection somewhere.
A bad connection on T1 is possible. I'd resolder that first.

73 Alan G4ZFQ