UTC A-26 Output Transformer

[CJ]

98 percent of the transformers i ripped open used lams that were 0.013 to 0.014

it is hard to buy anything else without getting a huge shipment,

 

[Cutterwoller]

Ah! Thanks CJ.

One thing confuses me, maybe im being stupid tho. If there are 37 laminates at 0.014mil, that would make the stack 0.518mil high. So a cross sectional piece of the core would measure 7.9mil (UI31 standard) by 0.518mil. This doesn't seem right to me. Or does it? How can the stack be half a mil high!? The picture of the UTC A-26 certainly didn't look half a mil high. Am I being stupid? Im kind of new to this.

Thanks for the help CJ, appreciate it.

Cheers, Lewis

 

[Cutterwoller]

So the 0.014 in in inches and not mil? It would make sense that way. On your (CJ's) spec sheet for the Y-6431, it says "0.014mil", I think thats what confused me. Or am I still wrong!.....

Cheers

 

[CJ]

ahh, me bad,  ???

mil is a slang used in some industries for 0.001 inches,

it is easier to say mil than one thousandth of an inch, get me?


easy to see how it could read millimeters,

transformer insulation is usually speced in mils, so watch out there also!

 

[rafafredd]

What???

1500 Henries / 8000 turns primary. Haha. OK... No one will ever wind these again. UTC was crazy!

 

[noulou]

What???

1500 Henries / 8000 turns primary. Haha. OK... No one will ever wind these again. UTC was crazy!

Apparently Oliver does. Check out the ut26 here

http://www.tab-funkenwerk.com/id53.html

 

[CJ]

Langevin made some  tube stuff before the fabulous AM-16 transistor units,

those tube transformers were crazy to wind, and unwind!  :

the A-10 is no pic nic either,

ollie must have a machine that winds 2 wires at once,

 

[Cutterwoller]

Thanks CJ, I thought that must have been it.

When one winds the coil, is it then taken off the bobbin in the case of the UTC because I dont see any bobbin on the pics. I have thought about making the bobbin form paxolin and then sliding that onto the laminates or is that a bad idea? Does anyone know a good place which explains how to wind the coil using the fish paper and all the gunk? I have this AVO coil winder from the 1950s which im guessing is up to the job.

Cheers

 

[rafafredd]

WOW, Ollie prices are not bad on those UTC repros. Much better than the official UTC buyer - Magnetika.

I heard there were winding machines at UTC that would wind 24 A10s at once. Probably to make it commercially viable, even 50 years ago. How many they could have produced? I guess too many. I know there are many NIBs around up to these days. hehe. And UTC used to call all these A-series miniature, and budget. Imagine what they put inside those big LS10s! 

CJ, that input and output Langevins I sent you for dissection was from 5116b electrodyne version. The mic trafo have very high resistance and inductance on the primary. If I recall it was more than 100R on the primary: almost 10x common microphone windings. Still, these are not noisy at all in the 5116B circuit, and sounds just WONDERFUL. Maybe they calculated the winding to match the tube selfnoise, and to present a high as possible inductance to the mic, without adding more noise than tube already did? Makes me think, as PP circuits are noisier anyway. And was the wise guy who said 12ax7's are sh*tty tubes? ???. Don't know what are talkin'bout.  : 5116B is probably the best sounding tube mic pre ever.  8) All those audiophools keep repeating on forums that "12ax7" is a bad tube. OK, tell me more about it...

What is the connection between Langevin and Western?

For reference:

http://www.groupdiy.com/index.php?topic=8196&highlight=electrodyne

 

[CJ]

12AX7 is ok if you get the good ones from 1950, 12ay7 is a great tube also,

those Langevins had a weird pine sap potting compound that made them extremely difficult to unwind, you had to heat up the coil, pull off 10 turns, the wires breaks, heat it up again, another 10 turns, all the way up to 10 million turns, by far the toughest unwind i have ever done,

nobody uses the LS iron from UTC, some of it is really good, some of those big cans have the same size lams that are in the smaller a-10 cans, just mega shielding, many nested cans o mu,

 

[lassoharp]

nobody uses the LS iron from UTC

You wouldn't guess that from the psychotic prices they sell for on ebone. 

 

[emrr]

author=rafafredd link=topic=35639.msg618809#msg618809 date=1339557402] And was the wise guy who said 12ax7's are sh*tty tubes? ???. Don't know what are talkin'bout.  : 5116B is probably the best sounding tube mic pre ever.

That was me.  I agree with the old texts - "hi-mu tubes unsuitable for low noise preamp stages". 

Someone should buy my pair of 5116-B's then, but no one seems interested.  I'm not wild about the way they sound, but that's just me.  There's yet to be a day I wanted to use them over anything else I have. 

I've been round and round here about the high resistance of Langevin and RCA iron.  No clear statements from the old dead guys, but I've theorized that it's about flattening the impedance curve and loading. 

 

[rafafredd]

No, it was not you that I was directly talking about. I was talking about most people on hi-fi forums.

Anyway, try the 5116B on piano. I never heard a preamp sound better on the piano. About the high resistance, it is really a question. If I recall, the primary of 150ohms in the 5116B iron was about 20H. 

 

[lassoharp]

I was talking about most people on hi-fi forums.

They are used in at least one or two McIntosh amps and those are exotic designs to say the least.

Excepting phono pres most of their stuff deals in line level apps.  But I guess some of them need a point of exclusion from the gitar amp crowd. 

iron was about 20H

And so you naturally ask what was going on with UTC A, HA and other similar units. 

The Cinemag, Sowter, and Lundahl ITs don't seem to miss the boat.