Please do take many pictures before you work on it, so that you can rebuild
it like the original. At some point, this will be a valuable investment if
it is maintained as carefully as possible but not updated or "made new".
Having said that, it would be very rare for a radio of that age not to have
suffered some decrepitude or been repaired at some point. If it has already
been hacked or has some blemish to repair, you will have lost nothing by
matching something in. Replacing a capacitor, tube or resistor wouldn't be
a big deal. Leaving brush marks or scratches on the chassis would be. At
some point, you or the next owner could rebuild or fabricate an original
part to match later. The object is to maintain the character and not to do
anything out of character that isn't reversible.

I wouldn't have a problem with cross posting of projects like these as the
technology of radio restoration is almost indistinguishable but for a
transmitter.

Batteries were often hooked in series to obtain the voltages and it was
common for a battery box containing many battery packs to take care of the
various voltages. This is impractical these days, because the last I saw of
these batteries was in the 80's (if you looked hard) and they were expensive
and didn't last long enough. It is possible to make an AC power supply for
all the voltages required. Once you have the schematic, there may even be
one there, as there were undoubtedly AC models of that radio. Indeed the
voltages are so common, you could easily build a much newer and efficient
power supply, carefully concealed to match. Look to back issues of QST or
ARRL handbooks in the library for the fast track to the technology. One
popular way of doing this after high voltage transformers got scarce, was to
take two filament transformers, one 6.3 or 12.6v ac to supply the tube
filaments and lamps, and another smaller one connected in reverse and
powered from the 6 or 12 volt to step back up to 117v ac, which is then
rectified and filtered for the appropriate DC voltage. This provides
isolation of the radio chassis from the house voltage. At this point even
filament transformers are getting scarce. At one time there were many
solutions available, but part availability has called for unorthodox
ingenuity, at least until you stumble onto what you need at the flea
markets.


"range hood" wrote in message
...

Hello all, I'm new to this forum. I may not even be in the correct forum
for a question like this, if anyone has a link for a better place for me
to go, I would appreciate it. I have acquired an old tube radio at a
garage sale. It just kind of looked at me and said "help me". I don't
have any experience rebuilding electronics, especially antique stuff. I
am handy with small parts and soldering. The radio is a Deforest Crosley
built in 1937 and is a battery operated model. I don't really know what
a B+ 135 volt battery looks like, I've never heard of anything like
that. Is it possible to use a transformer to convert AC to what I need?
I have ordered the wiring diagram, but don't have it yet. I am aware of
issues with old electrolytic capacitors, some of the threads I have
have read in this forum have made it apparent that they may have to go
in favor of modern ones. That is OK with me, I'm not too concerned with
keeping it all original, I just want it to work. If anyone has general
advice for me for a project like this, please feel free to respond.
Thanks. Norm




--
range hood