Repairing an output transformer

1/4/2013 1:45:34 PMScott

Restoring a zenith table radio that has a output transformer that is kind of beat up. The laminated/varnished layers of paper are gone from this side only. The primary leads are exposed (after some searching) but the connection wires are ripped out. The transformer ohms out ok. So I can reconnect the connection wires to primary but would like to reseal this mess so it looks like it should and also holds the connection wires securely.
Any recommendations on how to best accomplish this?
Thanks for any info.

1/4/2013 1:48:19 PMScott

Well lets try this link for photo.

http://i956.photobucket.com/albums/ae46/s1tracey/ZenithOutputTransformer001_zps48269bfa.jpg

1/4/2013 2:40:32 PMEdd

:Well lets try this link for photo.
:
:http://i956.photobucket.com/albums/ae46/s1tracey/ZenithOutputTransformer001_zps48269bfa.jpg
:

GREAT SCOTT ! . . . .

Now, that's one ratty looking transformer windings overwrap ?

What I do is take some thin posterboard stock and make a quasi square rounded U that will be of the width required for the winding width and the total other length dimension will be enough to cover half of the transformer up to the metal core.

Then make another cover for the other half.

An adhesive then fastens the two separate halves to the transformer.

If using new "stark" virgin white posterboard, multiple Coffee or Tea stainings can "age" its coloration for you.

Where you show the wire ends, I would lengthen /relead them and bring out from underneath the new covering

An unknown option, is if there is being adequate side core /to /winding clearance . . . and it looks not to be . . . .is to pass the posterboard length all the way THRU the core window for 1 1/2 or 2 wraps.

What I mean by the quasi rounded square shaping versus a half round is the outer SIDE OVERALL PROFILE being presented by the brown vinyl covering on this insulated staple:

73's de Edd

If at first you don't succeed, just go back and destroy all evidence that you had even tried !

1/4/2013 3:43:36 PMScott

Thanks Edd. Will try this method.
Have a good 2013.

1/4/2013 7:11:26 PMThomas Dermody

Contact cement would be a strong adhesive with a fair amount of work time. Varnish over the paper will hold everything together, gloss it up, and seal it up.

Sometimes you can disassemble the laminations, which allow better access to wrapping the outer paper layer.

When attaching the connecting wires, use friction tape, medical tape, or heat shrink to cover the solder connections well so that they do not rub through the underlying winding. Some manufacturers also give the wires a thick backing plate of cardboard. Others merely fasten the wires properly spaced to the first layer of outer wrapping, usually with something like bandage tape, and then, with glue and/or varnish, sandwich the entire works together with more wraps of the outer paper (something on par to grocery bag paper). Soaking the entire assembly there-after in varnish will give it much strength.

www.tubesandmore.com and www.radiodaze.com sell cloth covered PVC wire that will keep the transformer looking original.

1/5/2013 6:07:06 AMScott

Thanks T.D. for the specifics. Very much appreciate the detail on the "how to" complete the fix.