#qcx #problem #solution QCX Low/No Audio problem SOLVED #qcx #problem #solution


KB3USG
 

Hello everyone,

First, I'd like to explain the symptoms of my QCX when it wasn't working
in a way to try to document a mode of "failure" so that anyone else
trying to look for debugging help can find (at least) my failure mode.

I had an issue in which my newly assembled QCX transceiver had _very_
low audio.

* The sound level when trying to peak the BPF was unremarkable. I
turned the potentiometer all the way up to be able to hear the
sound. Since the manual warns you about the sound level, this
already had me wondering.
* The sound/noise in the receiver did not increase when I hooked up my
(homemade magnetic loop) antenna
* I could hear the clicky updates to the LCD as mentioned in manual.

After working on the aligning the radio and still not hearing anything
(and working on peaking the BPF), the radio finally made noise when I
was poking at it (and flexed the board).

I thought that I had an intermittent connection on the board (bad solder
join?) and finally remembering the caution from the assembly manual that
the potentiometer was delicate, I loosened it, and the radio came alive.

With the potentiometer over-tightened, the QCX had very low audio output.
Loosening it seemed to cure the audio problem.

So my initial problem is solved.

I have a follow up to this situation (audio hum), which I'll put under
separate cover.

Cheers,
Paul
KB3USG