Home Forums For Sale / Wanted Chisholm Model 369 Schematic Reply To: Chisholm Model 369 Schematic

Bruce Morgenstern
CVRS Member

Hi Jean & Gerry, sorry I didn’t reply to your posts sooner.
Jean, I know the missing connection will help me.

Gerry, Thank you for the offer of help, schematics, and information.

The Chisholm radio Model 369 was given to me from a friend who is a tube collector and seller, in Wenatchee, Washington. He got this radio included in a purchase of tubes and gave it to me. The radio looked in pretty bad shape and I was actually thinking of throwing it away until doing some research I came across your article, Gerry. Reading that it was manufactured in Vancouver made me take another look at it. I came to the conclusion the cabinet was sound but would needed a complete refinish, which can be done.

It was then time to look at the chassis and I thought I would just plug it into the variac and very slowly increase the voltage. I didn’t get the voltage turned very high until smoke was coming out of the transformer. Well what I found was astonishing and here is just a start of what I found; The original transformer was changed to a transformer that did not have a 5 volt winding only a center tapped high Voltage winding and a 6.3 volt winding. They then tried to replace the 5Y4 tube with 5U4 tube. The High voltage wires were connected to the filament terminals with gobs of solder flowing over one terminal to another. At this point I stopped as there was more and more of the same.

I have decided to repair the chassis using the Chisholm 540-530 schematic as it looks very close to what I believe this radio is.

Gerry, I am sure I will be back asking you for help as I go along.

Thanks, guy’s.