Any books on the esoterica of OT winding?

[skyboltone]

Some of these crazy people pay thousands for a pair of Western Electric output transformers.

I think mostly about bigger is better but:

Phil Heyboer recently tore down a very nice sounding OT from a Hammond Organ amp that I sent him and found different sized wires in the secondary windings. Little wires spliced to bigger wires, then the winding continued. He gave up trying to decipher it because the windings would break after every turn. So we decided to wind it his way.

The primary was wound "upside down" according to him. That's mysterious to me.

Weird eh?

Anyway, I'm finally building my "real" shop and I may try my hand at power transformer winding anyway.

Dan

[Structo]

Cool Dan.

I am envious of guys that have a shop for wood working and or electronics.

I have thought about winding some guitar pickups before.
You can find plans for the winders on the net.

Would you wind a transformer by hand or use a machine?

My dining room table (or should I say my wife's dining table?) reluctantly gives up it's surface for my amp and guitar projects.

After about a week of it being cluttered with parts and other junk I try to return it to it's pristine condition and try to hide the new scratch with a place mat that I put in the top with an amp chassis.......

[Andy Le Blanc]

I think there's one at pmillets book site, but its technical and not practical.

The 1937 ARRL has a short but practical section.

I'd ask Mr Heyboer for a list of the tech reference he has.

[skyboltone]

Cool Dan. Would you wind a transformer by hand or use a machine?

Machine wound of course I guess maybe. I've got scads of Hammond Organ Power transformers for instance that are ENORMOUS but very "soft" , 375-0-375 and only about 140MA. Not good for nothin' There's plenty of iron there for a 400MA transformer. Or so.

http://www.lindsaybks.com/bks11/xfmr/index.html

http://www.lindsaybks.com/dgjp/djgbk/coil/index.html

[skyboltone]

I think there's one at pmillets book site, but its technical and not practical.

The 1937 ARRL has a short but practical section.

I'd ask Mr Heyboer for a list of the tech reference he has.

Andy I don't have the 1937 but I got one from the '40s someplace. A lot of that material was carried over to newer issues. If not, could you scan the appropriate pages and send them to me? Gif or jpeg or pdf or whatever. Snailmail?

I would love to find somebody who worked at McIntosh in the '50s and still remembers something. Those guys knew how to wind a transformer.

Thanks
Dan

[David Root]

Have you seen this? Excellent practical guide by someone who knows. This is a hi-fi site but a really good one, run by a slightly prickly Aussie.

http://www.turneraudio.com.au/output-trans-winding.htm

[skyboltone]

Have you seen this? Excellent practical guide by someone who knows. This is a hi-fi site but a really good one, run by a slightly prickly Aussie.

http://www.turneraudio.com.au/output-trans-winding.htm

Thanks David. That does look like good stuff.

[Andy Le Blanc]

that is a good one.

The tools look very basic, it's like that with guitar pickups too.
once you've got the basic set up, it's more of how not to break the
wire your winding with.

[tubeswell]

DIY - I like the idea of his vacuum pump machine to extract air bubbles

http://crash.ihug.co.nz/~andrewp/Transformer.html

R.G. Keen's (incomplete) advice

http://www.geofex.com/article_folders/x ... former.htm

This page has a lot of info as well

http://www.turneraudio.com.au/output-tr ... ec-08.html

[skyboltone]

I got one of these. Now all I need is a turns counter. Atlas/craftsman 6" X 18". Most of the bells and whistles. I paid $175 Craigs List then added a quick change post and a bunch of cutting tools for another $100. I also have a vacuum pump. Kool.

[img:727:362]http://www.lathes.co.uk/craftsman/img21.gif[/img]

[M Fowler]

375-0-375 and only about 140MA

Wow I had to look hard to find a tranny with those specs and ended up with a Hammond that I hate.

That spec works great for Gibson EH150. Need 5v and 6.3v taps

Mark

[David Root]

Skyboltone, with that lathe and a vac pump you have it made in the shade! Turns counter is easily obtainable, I recommend a SODECO if you can find one, Swiss made, excellent quality.

Maybe we can get custom OTs from you.....??

Andy, I used to wind a lot of pickups until I got addicted to amplifiers. I still have an Edwards vacuum pump I used for potting......sheesh, now all I need is a lathe!

[Andy Le Blanc]

a treadle singer and the back side of a compressor pump work

you can adapt a cassette tape counter, or count clicks on the fly wheel.

[skyboltone]

375-0-375 and only about 140MA

Wow I had to look hard to find a tranny with those specs and ended up with a Hammond that I hate.

That spec works great for Gibson EH150. Need 5v and 6.3v taps

Mark

You want one? It's a Hammond Organ transformer out of M3 amp. AO-29?? Dang I forget and I'd have to go open the back of my organ to find out. AO-49? It's got the 5 and 6.3 V windings. Came with a 5U4 and about eight 7 and 9 pin tubes. Anyway it's bigger than a Bassman tranny.

What do you got for trades??

[skyboltone]

Skyboltone, with that lathe and a vac pump you have it made in the shade! Turns counter is easily obtainable, I recommend a SODECO if you can find one, Swiss made, excellent quality.

Maybe we can get custom OTs from you.....??

Andy, I used to wind a lot of pickups until I got addicted to amplifiers. I still have an Edwards vacuum pump I used for potting......sheesh, now all I need is a lathe!

It's got lots of speeds too. I run some stuff in the (to be finished) shop on 3 phase power (not the lathe) and I have a variable frequency drive that could run the lathe I guess, but really no need. But I'm pretty sure I'm gonna put it on the 1932 Boice Crane band saw. It's what you call a Snowflake. Fourteen inch with 7.25" of resaw ability.
[IMG:336:448]http://i41.tinypic.com/34gvvcy.jpg[/img]