[Hallicrafters] Cap replacement

[Robert Nickels]

I've never subscribed to the "replace 'em all" school of thought when it
comes to capacitors; if the circuit is working right, I leave 'em alone.
But that's why the S-76 I acquired a few weeks ago was still malingering on
my bench.  All stages seemed to be working fairly well, but it still "just
sounded like crap".  Feeding audio into the phono jack proved that the
problem lay upstream from there, and I kept coming back to the "selectivity"
control and the caps associated with it.   They were the same kind of
plastic encapsulated paper jobbies commonly known as "black beauties" and
while I wasn't totally convinced this was the source of the problem, I went
ahead replaced them all.

Short of jacking the cabinet up and driving a new chassis underneath, I
don't think I've ever heard a bigger improvement in the sound of a receiver!
The audio is now clear, and tuning across a signal iss smooth - all traces
of the mushy sound and what must have been a low-level oscillation in the 50
kc IF are gone.   The funny thing is, the old caps don't show much leakage,
but they don't show much capacitance, either.

The S-76 was marked the debut of the 50 kc IF and many subsequent receivers
used the same basic dual conversion circuit, so if you're not satisfied with
the sound of your Hallicrafters receiver, heat up that soldering iron!

73, Bob W9RAN