[Hallicrafters] S 38-D Oscillation

[Bill Gerhold]

One thing not mentioned here (I think), is the possibility there is a real
signal on the frequencies specified.  It could be coming from anything from
a battery charger to your TV even though it is off.  I would also see if the
signal disappears when you have disconnected the antenna.

I would try to kill the house electronics and then listen again to see if
the signal is still there.  Could even be a neighbors house.

K2WH

-----Original Message-----
From: hallicrafters-bounces at mailman.qth.net
[mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Brent Seres
Sent: Saturday, November 26, 2005 8:27 AM
To: hallicrafters at mailman.qth.net
Subject: [Hallicrafters] S 38-D Oscillation

Hi Folks

I'm looking for some help retoring an S-38 D. I have re-capped the unit 
and performed the alignment as per the service manual. The radio seems 
to be working well except for 2 minor problems:

1) On weak signals (especially on the BCB, below about 1200 kHz), there 
is an oscillation, much like a weak BFO signal that goes to zero beat as 
I tune through the station The BFO is off, the IF is aligned, and poking 
and prodding at components does not seem to have a significant effect, 
such as changing changing the amplitude or frequency of the note.

2) The bandspread is somewhat wonky, difficult to tune in SSB. I realize 
this receiver was not designed for such things, but it seams easier to 
tune the signal with the main tuning rather than the bandpread. I have 
re-strung both the main and bandspread tuning as per the diagram, and 
lubricated the bearings in the capacitor as best I could, but there 
still seems to be a fair amount of backlash in the bandspread.

If I could solve both these problems, I could complete the project to my 
satisfaction.

Regards

Brent  VE3CUS
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