[Collins] KWM-2a has no low audio on SSB output on 75 meters.

[Gerald]

On Sun, 2005-12-18 at 21:44 -0500, Cam and Juli Hedrick wrote:
> HI all, 
> Where do I start, I was on 75 meters tonight and the report of my audio was
> shocking? It has a hum and the low end of the audio is flat.  All is well on
> 40, 30, 20, 17, 15, and 10 meters when I looked at it on the spectrum
> analyzer into a dummy load, but 80 and 75 looks yucky.
> Output is also lower by 50 watts on 75 meters, I get 110 watts everywhere
> else.  I guess I need to put it on the bench and align it, plus test the
> audio output tube in the mixer.
> Any advice before I start?
> Cam
> WA4JKW   
If its only on a band, it has to be something switched with the
bandswitch and surely can be band switch contacts. It can be loading
trimmers, it can be crystal, switch contact problems are more than a
little common. It can be a ceramic trimmer with a contact problem.

With the propensity of the vintage ceramic trimmers to stick, an
alignment can lead to trimmer replacement that wouldn't have been needed
if the trimmers were making contact and were close enough.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer