[Arran]

I used "magic" tape between layers, don't know if that is good or bad or how long it will hold up. I was going to soak the completed winding in varnish (did this back in 1976 when I rewound a power xformer for a AK 89) but decided against it. The #37 is so fine I was afraid if I broke a wire during final assembley (which I did) it would be dificult to fix. I have the OT mounted on the speaker now but have yet to try it with the radio.

I've never tried rewinding a transformer before but have considered it and read some articles on the procedure. As far as I know "Magic" tape is fine, that is if it's the tape I'm thinking of, the frosted type that is made out of polyester or some other plastic. The stuff that is NOT alright to use is ordinary Scotch sticky tape, the tape itself breaks down and the glue goes with it, I believe that it may be corrosive. That is one thing that I have learned with splicing eight track tapes, Scotch tape is bad (glue goes gummy then the tape dries up and falls off) but Magic tape is fine if you can't get real splicing tape. Once you know that the rewinding job is successful you could take it to a motor winding shop and have it dipped, if the price is reasonable, they vacuum the air out so the varnish gets into all of the layers.
Regards
Arran