[Hallicrafters] S-38 audio question

[Craig Roberts]

I've just carefully and thoroughly restored and aligned a couple of little
S-38s to give away as Christmas presents to friends. One is an S-38A. The
other is an S-38C.  The circuitry differs a bit as does the factory build
quality. The earlier model was well put together with neat solder joints and
nicely dressed leads.  The 38C, on the other hand, displays much sloppier
assembly and suffers a little in performance.  For instance: the 38A dial
tracking is very accurate (especially considering the unsophisticated
circuitry). The 38C is not nearly as precise.  The 38A's audio is clean with
good AVC action-- even on a 50KW broadcast station just about a mile from my
house.  The 38C, however, can't handle the BC signal and overloads easily.
The 38C's volume control does not attenuate a strong signal as well as the
earlier model's, either.

I've replaced all caps, with the exception of the micas, in both receivers.
Resistors have been checked and a few have been replaced in both. Both have
been outfitted with new tubes. Sensitivity and selectivity are about equal,
but the audio quality in the 38C is noticeably less than that of the 38A.

Any ideas on how to improve the AVC and volume control effectiveness in the
38C? It'd be fun to bring it up to snuff.

73,

Craig Roberts W3CRR

Oh yeah -- Hi Glen!