[Hallicrafters] SX28 again

[Guido]

Finally I decided that I had the time and energy to haul the SX28 from the
top of the R12 speaker and into my working table. No. I don't have a
separate shop for working on my BAs. The shack becomes the work area and for
a time it is a mess. Then it transforms again into a rather neat shack. Back
to the SX28, the work involved replacing the audio transformer with an
original kindly supplied by a fellow BA collector. I had noticed that
crackling noise that comes from dirty main tuning wipers so I went over them
with some contact cleaner and then a bit a my favorite, WD40. Behold, the
crackild disappeared and overall response in all bands was great but nothing
is for free. Now I have to go through a whole alignment of the RF circuits.
It seems that whatever dirt or oxidation was there had enough effect that in
some bands the frequency had jumped almost 50kc !. Go figure, I never
expected this response from just cleaning those contact points. BTW, the
replacement audio transformer also replaced the tremendously excellent audio
of the SX28.
 
Best 73s
 
Guido Santacana KP4FAR