UTC S-20 modulation transformer

[Quayhog]

I have acquired a UTC S-20 modulation transformer.  It's a 55 watt suitable for PP 6l6.  I can't find any undstandable data for use in audio, specifically guitar or bass amp.  It's a beautiful transformer but I fear it's another doorstop.

Has anyone ever used this in a non radio transmission audio circuit? 
The few schematics I've seen all show driver tubes and interstage transformers.
Would it work in a typical Fender type circuit with commonly available 4 ohm to 16 ohm speaker?

 

[emrr]

Modulation is typically a step-up interstage, so no.  Data should be in the UTC catalogs, many online. 

 

[PRR]

> I can't find any undstandable data

Google "UTC S-20 modulation transformer":

http://www.junkbox.com/electronics/utc_transformer_catalog_1963.pdf
Cost $15 new in 1962. (About the same today, scratched.)

http://amwindow.org/tech/htm/modtran/utc/sseries.htm
"S Series Terminal Arrangement"
typical: 4000CT to 17500, 12500, 8600, 7300, 4300, 2150, 400, 4000, 5500, 3500, 3000, 1850, 1400, 250 (with pin connections)

http://www.technicalaudio.com/pdf/UTC_United_Transformer_Corp+TRW+OPT/UTC_United_Transformer_Corp_Type_S_terminal_arrangements_1954.pdf

So if you have a several thousand ohm load, and accept voice bandwidth, this is your puppy. Otherwise it may be your doorstop.

The only "obvious" use today is the original (AM modulation of a 100W tube transmitter) or to smack big grid power into a couple large transmitting triodes to make 500W-1000W of voice-grade audio.

It could have a use in prototyping. Like any big CT transformer, you can wire a pair of tubes to it, bridge a 2K to 8K load across the ends, measure output, and find optimum load impedance for specific tubes, B+, and bias. But an old Bassman or Plexi OT will do the same, and you don't have to stick to the center of the voice band.

> with commonly available 4 ohm to 16 ohm speaker?

Sixteen 16 Ohm speakers in series makes ~~250 Ohms which the S-20 will transform to ~4KCT, suitable for a 50W pair of tubes.

 

[Quayhog]

So for standard audio it's useless,  as I suspected.  If any DIYrs have a need for this you can have it for the cost of shipping. 
Otherwise it will become a doorstop for my shop door.
Thanks for the replies.

Jonathan

 

[CJ]

might work well as an active DI xfmr,

 

[emrr]

Nothing says you have to put PP multi-watt power into it.  It may work great as a 1W direct coupled single ended preamp or line amp transformer.