[AMRadio] 3 kV CT transformer

John Lyles jtml at losalamos.com
Tue Dec 19 15:13:56 EST 2006

Jack, K9ACT, before you pay Peter D. to make a new transformer, I wanted to tell you that EBAY has transformers that meet your needs quite often. Search under HV Transformers, and Plate Transformers as keywords, and you will find various parts. You have to look through a list of microwave oven transformers, photocopying transformers, and TRANSFORMERS, those little toys. Buried in there you will see occasional Westinghouse, UTC, GE, and so forth. Depending on the current you need, a 3 KV CT (good for a little under 1400 VDC output with a choke input) might cost about $30-50 on EBAY, if you are lucky. 

1100-0-1100 to 1500-0-1500 secondary transformers are much more common than 2500-0-2500 and up. So they don't cost as much. The higher voltage high power models go for >$100 typically, sometimes too much. 

Depending on your current requirement, you might need something like a UTC 303, 311 or 312. The first is 22 lbs, but the second two are 50 lb units. These were the commercial grade UTCs. Their S Series S-47 or 48 might also fit your needs, weighing 24 or 31 lbs. These are all still found surplus if you look for them. Stancor, Chicago, Thordarson, and Triad all made something in this range also. If you don't mind paying for shipping and crating, I could probably find something either in my shed or at the local junkyard that will be one of these. 

Here is a store on EBAY, that always has plate transformers, sometimes large. I have bought modulation transformers from them: 
"Uncle Henry's Basement. Antique Electronic Parts and Equipment for the DIY Audio and Radio enthusiast. Tubes, Transformers and more!"

Hammond in Canada also makes a very reputable line of transformers to meet your requirement, with their 700 series: 

Good luck, finding iron isn't as hard as you think, but you have do more than post classified wanted ads to get them. 


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