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Replace or repair power transformer?
#1

Philco 91 model - I don't know if mine's shot because I'm waiting on some test equip. from an ebay guy who hasn't gotten back to me, so I ask this in general: if mine is ruined, are replacement power transformers hard to come by or hard to repair?

This is what mine looks like from the outside, apparently some sort of leakage? If so, it's the only outward sign of possible trouble I see.
[Image: http://i.imgur.com/imE8wBn.jpg]

Is it wise to open it up just to inspect visually? If so, what would I look for?
Thanks.
#2

You can test the windings of a transformer with a regular Ohm meter, it's won't tell you everything but it can tell you whether one leg of the high voltage winding has a different resistance then the other or whether a winding even has continuity. Most schematics give DC resistance measurements for the transformers. Generally speaking if a power transformer has failed catastrophically you can tell just by the smell, it smells like burned varnish or a burned out motor, with a burning tart smell thrown in. If you can see the core of the transformer it will also look burned. Normally the leads going into it will also look burned and there will be a puddle of tar bellow the transformer, not just a little residue but blobs. I don't think it's too difficult to open the metal bells on one of these, just undo the bolts going through it and it should spread apart with a little persuasion. The model 91 used 6.3 volt tubes I believe so it should be as hard to replace the transformer as an earlier set, it's also vertically mounted as most newer off the shelf replacement transformers are.
Regards
Arran
#3

The transformer might still be good. I have seen some in worse shape that were still good. It might have just gotten warm. As Arran suggested ohm out the transformer and make sure it still has continuity. If it tests good then you can power the set up with all the tubes out and see if it gets warm with no load. If it does it's pretty much junk. If it stays cool I would proceed to restore the radio.

You can pull the bells off the transformer but there is two tabs that fold over on the bottom. You will need to take the transformer loose from the chassis and bend these tabs straight for the bells to come off. You can see the tabs in the picture from my Philco 71.

[Image: http://i1129.photobucket.com/albums/m501...AG0774.jpg]

-Keith
#4

Ooh man that's a shiny one, Keith.
My ebay guy finally came through today, now I can check it out. Thanks for the input, guys.




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