I am restoring a couple of S-40B receivers, and I am interested in finding a
replacement power transformer. The transformers that came with the radios
appear to have moisture in them, probably from years of storage in a humid
environment. The one transformer that I have tried to power up on a variac
started to sizzle when I got to 50 VAC on the primaries, so I powered down.
I plan to attempt to dry out the old transformers, but I would prefer to
replace both with new, known to be good units.

I have looked over the offerings from Antique Electronics Supply, and their
Fender transformers are a close match. Unfortunately, the Fender
transformers offered there top out at 325-0-325 V for the secondary
windings. I need a transformer with 350-0-350 V / 70 mA, 5 VAC / 2A, and
6.3 VAC / 2.6A secondary windings.

I would also be interested in finding out a place to send the old
transformers for rewinding if nothing is available for replacement.

Meanwhile, while I search for replacements I plan to attempt to dry out the
old units by removing their shell covers and sealing them in an airtight
container with silica gel for a dessicant, for about a week to ten days. I
have read of techniques for drying out transformers that involve running a
low DC voltage in the primary for several tays to heat up the transformer so
that the water could be cooked out. The risk of arcing and/or electrolytic
corrosion makes this approach seem risky to me. I am not particularly
interested in setting up an oven to passively dry out these things, so a
chemical dessicant seemed a reasonable approach. I work in a university
chemistry department, so if I can find some sort of vacuum chamber, I might
try to remove the water that way also.

The sizzled transformer mentioned above was not an original Hallicrafters
unit, but some sort of replacement that a prior owner used (vinyl covered
wire leads vs. cloth covered in the radio). I have two other transformers
that are original Hallicrafters units, but given their age I am not
optimistic about them.

One of these radios is a gift for my father, so I would prefer a "new"
replacement transformer that I don't have to worry about leaking current or
eventually going up in flames.

Thanks in advance for any suggestions or ideas that can be offered

Steve Burrows