Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

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.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
12' Philco
If it is 12', either Kareem or Andre would have to jump pretty high to look at the front panel. Kareem would have an e...morzh — 01:48 PM
12' Philco
And here's a story about the tires on the truck. Same "no-stoop" guy must have installed these! Take care a...GarySP — 01:17 PM
Hickok AC51 tube tester
I think they have only shown the secondaries of the transformer. Two of them feed the rectifiers' filaments.morzh — 12:58 PM
IF can wire size and Rubber mounts?
Arran If the wire inside cans is the gauges you mentioned, the sole reason for that would be mechanical, to stiffen t...morzh — 12:56 PM
12' Philco
Rod, Yes, I know, but the Giant Philco is not around anymore either, so I go by whoever was alive fairly recently. H...morzh — 12:54 PM
Hickok AC51 tube tester
Absolutely no one is going to reverse engineer that circuit. Even the iron core is missing.RodB — 10:37 AM
IF can wire size and Rubber mounts?
Thanks to both members for your help regarding wire and tuner mtg supports. regards--Johngeorgetownjohn — 09:33 AM
Hickok AC51 tube tester
Note that no power cord, power switch, or power transformer switch are shown. That (along with my experience with full s...DaleHCook — 07:09 AM
IF can wire size and Rubber mounts?
A pair of wire strippers can give you an idea of what the existing gauge of the wire leads are in the IF can, I think it...Arran — 06:07 AM
My last cabinet for this year
Hello Dan, That is really beautiful what great looking radio you have ! I have friends who live in Calgary and the wea...radiorich — 01:51 AM

[-]
Who's Online
There are currently 4480 online users. [Complete List]
» 5 Member(s) | 4475 Guest(s)
AvatarAvatarAvatarAvatar
Avatar

>