I'm new to this forum. I have all available information that I could find on this model and the Power Transformer High Volt (B+) Secondary is not specified. Voltage Table lists 248 Volts on 5Y3 Rectifier, 235 volts on Plate of 6F6G audio out and 248 volts on screen grid of 6F6G. Those are the highest B+ readings in this 5 tube set. Can anyone venture a good guess on the center tapped high voltage and current rating for the transformer? For what it's worth, physical size of transformer is about 2 1/2 X 3 X 3 1/2 inches. I really hope to get this nice set alive again! Thanks.

Never seen any hard fast rules on power transformer replacement. Others fell free to comment.

Used the schematic for Fairbanks-Morse "Chassis 58" that matches your note. Did not see a "Model 58" per say.

To begin with a 5 tube radio of this era typically draws 60 mA of B+ current.

The tube manual shows the 5Y3 tube rectifier would drop approximately 100V at 60 mA for a full-wave rectifier. With 248V given on the cathode of the 5Y3.

(248V + 100V)/1.414 = 246V RMS

A 250-0-250 volt at 60 mA trsnsformer is suggested. Richard

Richard,
I can't thank you enough! I looked at a number of power supply circuits that employ a 5Y3 rectifier to power 5 or less tubes to try and get a sense of what my set requires. The fact that the audio output tube is powered at less than its maximum rated voltage in this model and the physical dimensions of the transformer were also modest leads me to suspect the original transformers B+ secondary was under 300 volts AC. Thank you very, very much for confirming my suspicion about the values. Regards, Daniel.

:Never seen any hard fast rules on power transformer replacement. Others fell free to comment.
:
:Used the schematic for Fairbanks-Morse "Chassis 58" that matches your note. Did not see a "Model 58" per say.
:
:To begin with a 5 tube radio of this era typically draws 60 mA of B+ current.
:
:The tube manual shows the 5Y3 tube rectifier would drop approximately 100V at 60 mA for a full-wave rectifier. With 248V given on the cathode of the 5Y3.
:
:(248V + 100V)/1.414 = 246V RMS
:
:A 250-0-250 volt at 60 mA trsnsformer is suggested. Richard
:
:
: