Paper falling off of output transformer. Any fixes?
- Thread starter ExcitableOne
- Start date
Transformers of that era were typically soaked in varnish to glue the windings together and prevent windings from buzzing. During that soaking the paper would be saturated. This suggests using the same technique to preserve the paper. Ideally a varnish which will not yellow or become brittle over time.
I would not trust PVA (white glue) or similar acrylic because of the water content. A petroleum-based varnish will have the solvent evaporate and the transformer can be gently heated to ensure a full cure.
Hot glue, btw, is a thermoplastic, and tends to be hard and rigid. It also is not clear.
I would not trust PVA (white glue) or similar acrylic because of the water content. A petroleum-based varnish will have the solvent evaporate and the transformer can be gently heated to ensure a full cure.
Hot glue, btw, is a thermoplastic, and tends to be hard and rigid. It also is not clear.
ExcitableOne
Active Member
Its funny, right after writing this a wire fell off with no clear indication as to where it would solder back on.
I guess i get to look at spending $60 on new output transformers unless i can find where the tap is.
century tek
Addicted Member
How did it get ripped open in the first place? If you can find the wire, it can be resoldered being careful not to damage the protective coating on the other windings. I have done it but you might have to peel off more paper to find it.
ExcitableOne
Active Member
Found it that way. Couldn't see anything but tubes when I bought it it, figured for $20 it was a worthy deal. Turns out its an Admiral 5K5A, which seems well regarded.
If you cannot yourself fix this, I suggest sending it to one of the transformer rebuilders for repairs.
Should be an inexpensive fix—certainly less than a rebuild—and you will maintain the same sound.
If it is unfixable you have lost nothing other than some postage, and a new winding may be put on the original core for close to the original characteristics.
FlaCharlie
Super Member
Here are the specs for the OT along with suitable replacements by various manufacturers.
sKiZo
Hates received: 92644 43.20°N 85.50°W
Definitely looks damaged, not just an age thing. Wouldn't be surprised to find that the wire that fell off was actually dislodged same time the paper got ripped.
And ya ... given that you know the model number and replacements are available, sounds like a no brainer if you figure it's worth it ... I'd also check to see if stronger iron might be available, as a lot of that iron was pushed hard to make a price point ...
And ya ... given that you know the model number and replacements are available, sounds like a no brainer if you figure it's worth it ... I'd also check to see if stronger iron might be available, as a lot of that iron was pushed hard to make a price point ...
primosounds
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Your trans can be repaired if you want to try. It seems that the wire lead got pulled and yanked off its connecction to the wire around the tranny bobbin. The 2 wires are soldered together then usually glued in place followed by the paper cover. The internal wire is magnet wire which is varnished so hard to solder to unless all the varnish is removed. Also you need a hot iron. You should probably test the tranny primary and secondary resistance before you repair it.
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