Replacing Tattered Cloth Leads On An Old OT

[Structo]

The manufacturer pots the transformer with a type of varnish.
This is usually done in vacuum pots.
It is a rust protector and helps vibration noises.

Here is Magnetic Components twist on it:

We use a special formulated varnish resin to impregnate our transformers.
This varnish is a high quality, custom formulated, high temperature (Class H),
high thermal conductivity and 100% solids varnish resin.
Our varnish does not contain solvents like most off-the-shelf varnish used
by many of our competitors.
This resin provides a cooler, quieter running
unit with no trapped moisture that may shorten the life of the transformer.

Our military style varnish impregnation process is also special.
We preheat, vacuum varnish and oven bake cure our transformers for 8 hours for incredible mechanical
and electrical performance.
In combination with our special varnish, our varnishing process also helps eliminate trapped moisture.

[dynaman]

That's a nice and neat job ya did there, rp. A bit of solder on the joints wouldn't hurt. I notice you did trim the extra leads and just left them in the endbell - makes for a neater job.

Thanks for posting the pics, as I'm sure they'll be a big help for others in the future.

Yeah, solid core sucks, and even worse is when you run into a lead that's made of TWO leads of untinned solid copper wire sleeved in a single run of weaved insulation. The wire is almost always oxidized or has some nasty black stuff on it. In those instances, I just sleeve the whole lead in heat shrink tubing to preserve the remaining insulation and don't even bother to "lengthen" those leads in the endbells. I prefer to terminate those bastards outside of the transformer. Usually just wind up soldering them to a terminal strip or impedance selector switch (if length allows). Don't even try to solder those wires without cleaning the crap off the stripped end. I split the wires just a little bit and scrape them with an exacto knife until I get to shiny raw copper. Blech.

Nice job! Maybe you could even make some repop Stancor stickers!

On second thought, that might just lead to counterfeit 3801s!

[rp]

The manufacturer pots the transformer with a type of varnish.

Ah! It's the potting varnish on the leads. It never occurred to me they dunked the whole thing or it just absorbed down the leads. I could never figure out why the cloth leads on trannies looked varnished but not the cloth in the amps. And I see excess varnish on PVC leads all the time. Pretty obvious, duh!

A little amber shellac an this old trannie will look like it never left 1955. I got some extra cloth wire to experiment on.

[rp]

That's a nice and neat job ya did there, rp. A bit of solder on the joints wouldn't hurt.

Oh, they are soldered, I don't plan on taking these bells off again.

Yeah, solid core sucks, and even worse is when you run into a lead that's made of TWO leads of untinned solid copper wire sleeved in a single run of weaved insulation. The wire is almost always oxidized

Yup, you must have been inside a Stancor or two. Scraped them shiny with an xacto and then steel wool. Little scary is that they act like stiff levers going back to the winding.

Any idea what the double ones are? Does this help indicate whether it's the 4 or 8 ohm? Check Marcoloco's post to my tap ID questions here, I re-enc'd his map: https://tubeamparchive.com/viewtopic.php?t=12854 i guess once I hook it up I can check the voltage at the speaker with each tap too.

Nice job! Maybe you could even make some repop Stancor stickers!

Repo nothing! Once I get my all tube analog time machine working I'm going to import them from the past, charming Victorian badges and all!

[rp]

One last post before putting this to bed. Here it is with a little orange shellac on the leads. I didn't bother to thin it as it looks more authentic this way. Looks absolutely fantastic now, came out exactly as I hoped - nice when that happens. It's gonna mate up well with a pair of these tubes too:

[wsaraceni]

do any of the transformer companies redo their leads if you wanted to go that route?

[v846]

do any of the transformer companies redo their leads if you wanted to go that route?

IIRC someone here posted they had Heyboer do it, not sure on the price you'd have to contact them for the details.