UTC 5946 (UA 175b, and 610a Transformer)

I am trying to find some info about the UTC 5946 Transformer for a UA 610 and 175B build I am trying to do. I can't seem to find any real information about this transformer. I've read that this transformer is essentially an A-19 wired in reverse, but I'm not sure if this is completely correct or not. I know that the drip website recommends a sowter transformer as a replacement in their build, but I'd really like to get the original (or at least some UTC/Triad equivalent) for my pre. If anyone has any information at all about this transformer (and any info about transformers used in the original 610a/175b and suitable substitutes) it would be GREATLY appreciated! Thanks!

this is as far as we got the last time round,

maybe we can improve our knowledge, let me ask doc hoyer if he has anything more...

do a search here on 610 and you get a bunch of hits also...

http://www.twin-x.com/groupdiy/albums/userpics/UA176-177-OutputXfmr.jpg

Ian said:

I've read that this transformer is essentially an A-19 wired in reverse, but I'm not sure if this is completely correct or not.

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Interested here as well. The A-19/A-18 was used as the interstage transformer, not as an output.

Mark

ok, this xfmr was made by

Electro-Engineering Works in San Leandro, CA.

but they,>Magnetica now, no longer have the winding information.

get a gapped  7:1 and you will be very close to the original.

the taps i do not know about.

back then, it was AM radio only, so bandwidth did not matter.

this is why Sowter says his is higher bandwidth, we "modernized" the design a bit.

slightly lower ratio, probably more interlayering than the original.

look at the UTC can size, guess at the core size,

Do you know what kind of cores these UTC transformers have? I think I might try to wind my own as an experiment. Is there 'go to' place for laminations, bobbins, wire etc needed to wind a good output transformer?

this will get you real close to the original>

In case you haven't come across these during your research:

http://www.groupdiy.com/index.php?topic=32729.0


http://www.groupdiy.com/index.php?topic=23825.0


B version PP as well?  A-24, A-26?

you need a bigger core than that i believe,

the stock core will take about 18 db for a dc  p- p xfmr.

i saw another version of this OPT that was a 7:1.

the core gets about 4 k gauss at 20 hz, so you can use a 50/50 alloy possibly?

Hi Guys: If any of you are interested I have 4 sets of UA transformers. One set is from a 1008 pre & the other 3 are from 1016's. The input transformers all look to be the same. The 1008used  a 12AY7 for theoutput& the 1016's could have a 12AX7/12AY7 for output if it was used as a mike pre/booster amp, or a 12BH7 as a line amplifier This is stamped on the transformers.

They came out of complete preamps. I had a client when I had my studio service co. in Nashville 79; he had aquired a console built with these UA amps. These were left over & I stripped the transformers off & discarded the pcb's & sheet metal last year. There was no hope for any of the old components & pcb's were made from cheap laminate. The 1016 circuit is balanced & should producea nice fat sound.

Thinking of putting these up on ebay unless someone here is interested.

Bill Wilson said:

Hi Guys: If any of you are interested I have 4 sets of UA transformers. One set is from a 1008 pre & the other 3 are from 1016's.

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Cool!

Definitely interested in a set Bill, I'm building a UA175 in the near future and it sounds like these would work perfectly.

If you'd like, we can continue by email, Mark [-@-] SharktankPro [-dot-] com

I send you a PM as well.

Mark

interested in the 1008 output trafo... Are any of these a PA5946?

Ian said:

Do you know what kind of cores these UTC transformers have? I think I might try to wind my own as an experiment. Is there 'go to' place for laminations, bobbins, wire etc needed to wind a good output transformer?

Click to expand...

I'm interested of this too.. What's the most versatile place to order these in Europe? Any big differencies in prices between shops?

-J

paging Dr CJ.... Ever take one of these apart??

Could anyone link to the BA2A schematic? I never seen it...

hmmm... Would that be the same as BA2C???