The AM Forum

I got an NOS UTC S-9 for a Christmas present. Super! Original box and all...even the gasket but no wiring diagram. Help! This is for the 811A modulator with the 175 watt Hammond modulation xfmr. I know the specs and pin outs are floating around somewhere. Also looking for a chassis source...again. My old e-mail adr crashed so I lost a lot of contacts.  Reply direct to mike_kuehl_sr@yahoo.com.  73, MK the DJ A.K.A. "The Night Creature". You can call me Creech for short. ???

Is that an S-19?
If so: http://www.amwindow.org/tech/htm/modtran/utc/sseries.htm


If not then try this if you have highspeed:

http://www.duntemann.com/12vtubes/utc_transformer_catalog_1963.pdf

will probably have it, if it was still made in 1963...

More here:

http://bama.sbc.edu/utc.htm

And some site that I rarely visit has a 1938 ('39 maybe?) catalog:

http://amfone.net/Tech/online.htm    :D ;D :D



           _-_-WBear2GCR

If you don't find it, check www.bunkerofdoom.com and see if it's in one of the transformer catalogs. I would check but I am on an 8KB connection in Wichita, KS.

 :-\ Hello Dere'! No doubt this is an S-9. There were three transformers UTC made; interstage bad boys including the S-8 which may have been designed more for single-ended driving. The S-9 was designed for p/p drivers. It is made for 20 watts audio w/response of 100Hz-10KHz. There was also an S-10. I really need the pin-out for the sec of a classic UTC S-9. Da Mix

Hello,

My UTC data book lists the S-9 along with the S-1 through S-22 as "Special Series Audio Transformers". The description for the S-9 Universal Driver Transformer is:

"Pushpull driver plates to grids of class B tubes up to 400 watts output. Ratios can be set for 2.66:1, 3.6:1, or 5:1.  Max Watts: 20  Case style G-4"

Unfortunately, it instructs the user to: refer to the "Chart supplied with the unit for tube types, ratios are Pri to 1/2 sec." The picture shows a model S - 18 with a chart on its case, but it is too small to be readable, even if it did apply as well to the S - 9.

The book does offer a list of secondary taps to use with various tubes that the S-9 might be used to drive:

S-9 secondary terminals driving the following P-P tubes:

1 - 1    for pair of 807's
2 - 2    for pair of 6146's
3 - 3    for pair of 809's
2 - 2    for pair of TZ-40's
2 - 2    for pair of T-756's
1 - 1    for four 6L6's
2 - 2    for pair of 35-T's
1 - 1    for pair of T-55's
2 - 2    for pair of 830B's
3 - 3    for pair of 203Z's
1 - 1    for pair of HK-354's
2 - 2    for pair of 100TH's
2 - 2    for pair of 838's

Note:  Use the S-9 transformer installed backwards for driving a pair of HK-154's with terminals 2 - 2 on the plates of the driver tubes and P - P on the grids of the HK-154's

That's all the 1962 - 1963 UTC book offers on the S-9 Universal Driver Transformer. Oh, it was listed for $8.70 back then.

Maybe that's enough to get you close to a good match with your application. Good luck!

Rob W1AEX

NOTE:  Looks like my information here is a bit redundant as BEAR pointed to a pdf that is a duplicate of my actual UTC data book. All of the above is available on page 48 and 49 of the file BEAR pointed to.

 ;D ;D ;D Rob, I think you got it!  The  809 is just the kid between the 807 and the 811 so those same terminals should be OK for the 811A grids to work. I'll dig in more after the parts I bought get here. I need to start doing some serious chassis lay-out work. I'll keep you posted. Thanks a heap!!!!! Please contact me at mike_kuehl_sr@yahoo.com. I'm really getting fired up. We're having the roof worked on soon and the contractor is putting some heavy-duty stuff up there fine for mounting a rooftop tower. Da Mix