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Philco 53-564 IF transformers - Printable Version

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Philco 53-564 IF transformers - Tubeglow20 - 03-08-2020

Hello, I have been working on a Philco 53-564 repairing the IF transformers; silver migration disease.  The first transformer went well. Got the transformer out of the can, drilled the brass rivet out, bent the metal tabs back holding the mica piece in and removed the mica. Went back together perfectly. Checked the coils to make sure I didn't break anything, and all was good. The second transformer didn't go so well. It's the kind that has six pins on it instead of the usual four. Everything was going great until I was putting the transformer back into the can. Somehow one of the wires was broken along the side. I looked at the wire under a loupe and noticed that the wire was corroded and green. I think the radio might have been stored in a damp location. Tried to solder the wires back together and you know that usually doesn't go to well. Yep, the wire broke so the transformer is no good. Ok, I obtained another transformer and want to use it to replace the one that is now junk. It looks almost exactly like the one that came out of my radio. Made by Automatic Manufacturing with the brass rivet.....you all know the type. I have a question.......the original transformer measured approximately 16 ohms on the primary and secondary windings according to the schematic.  The replacement transformer measures approximately 16 ohms on the primary and approximately 17 ohms on the secondary; more like 16.8 ohms. Im wondering if this difference will cause any problems in my radio. The original transformer also had two extra capacitors and a 47k ohm resistor built in to act as some kind of rf filter. I can make that filter outside the replacement IF transformer.

RE: Philco 53-564 IF transformers - radiodale - 03-08-2020

Resistance difference is not a problem. Make sure to put the external parts on the proper leads.

RE: Philco 53-564 IF transformers - Jake Blake - 03-09-2020

Philco finally came to their senses and put that 2nd IF transformer inside a can by 1953,....but it is essentially similar to the  2nd IF transformer I botched in the 39-6 C I . Had they done that in 1938 , I wouldn't have made my mistake of pulling one of the wires off the transformer. ( I ended up re-winding the secondary winding by hand....horribly-sloppy but it works!)

It does look like you could add in the 2 extra caps with a terminal strip.  The entire assembly was exposed previously, so your mod may still work ok without horrible side effects, but pay attention to where the 47,000 ohm resistor is , in relation to the caps.