[Boatanchors] Patterson Power Supply Help Needed

[Drew P.]

WA5CAB wrote:

 " Joe is NOT looking for and doesn't need an audio transformer.  The one in
the radio is probably still good.  The field coil on the missing speaker
has nothing to do with the output transformer.  It is an electromagnet that
doubles as a filter choke.  Only one winding.  NOT a transformer.    What Joe
asked was what would be a reasonable resistor value to substitute for the
field coil in the DC supply so that with a permag speaker he could find out
whether the receiver works or not.  Before going to the trouble to find a
suitable voice coil speaker or a physically and electrically suitable filter
choke with which to convert the receiver for a permag speaker."

Looking at the schematic for this radio, I see a 4 pin connector where a field coil and output transformer should be. This radio uses a common arrangement for the era, where the output transformer is mounted to the speaker.  If Joe does not have the defunct original speaker from which to salvage the mounted output transformer, then he will need to get an output transformer as well as a field coil/choke substitute. Mouser carries tube-type (made by Hammond) output transformers and also filter chokes.

Drew