Triad Transformers

67supertrem · Post by **67supertrem** » Sun Nov 21, 2010 4:01 am

I purchased 2 used pair Power and Output Triad Transformers, PT PN# R-80BA/BC and OT PN# TY-67A. The OT states it will put out 40 watts, 300-3000C.P.S. They are used but appear to be in good condition with 3" to 4" leads and no rust on the iron. I bought them in hopes of building a wreak or a bassman. Has anyone had any experience with these transformers? Would they work in either of these applications?

David Root · Post by **David Root** » Sun Nov 21, 2010 4:37 am

This is a transistor OT. See Triad archive 1969-70 page attached. Not for tubes, sorry.

Could not find an R80-XX or even R80 PT between 1951 and 1980. However I think that R series was plate and filament type. What is written on the PT?

67supertrem · Post by **67supertrem** » Tue Nov 23, 2010 2:55 am

Too bad about OT's. Oh well, didn't pay that much for them.

PT: R-80BA/BC Power Transformer:
BLK PRI 115V, 60 C.P.S. BlK, BLU +6.3A. AT2.A BLU, RED 550V. R/Y C.T. AT 300MA D.C. RED, GRN 6.3V AT BA GRN/YEL, BRN 6.3V AT5A BLK/YEL,
YEL 5V AT 6A YEL.
*= START OF WDG
+= DAMPER WDG.
On the bottom of the PT: 32 under a triangle inside a circle.

Looks like it will run a rectifier tube and tube heaters? Not sure if the PT will have enough current?

67supertrem · Post by **67supertrem** » Tue Nov 23, 2010 2:59 am

Too bad about OT's. Oh well, didn't pay that much for them.

PT: R-80BA/BC Power Transformer:
BLK PRI 115V, 60 C.P.S. BlK, BLU +6.3A. AT2.A BLU, RED 550V. R/Y C.T. AT 300MA D.C. RED, GRN 6.3V AT BA GRN/YEL, BRN 6.3V AT5A BLK/YEL,
YEL 5V AT 6A YEL.
*= START OF WDG
+= DAMPER WDG.
On the bottom of the PT: 32 under a triangle inside a circle.

Looks like it will run a rectifier tube and tube heaters? Not sure if the PT will have enough current?

Cliff Schecht · Post by **Cliff Schecht** » Tue Nov 23, 2010 3:46 am

You've got enough juice in that transformer for 2 rectifiers, a pair of KT88's and a lotta preamp tubes. I don't think you'll be running a quad of big bottle output tubes but pretty much anything below that is fair game.

67supertrem · Post by **67supertrem** » Tue Nov 23, 2010 4:10 am

Great... Sounds like a JTM-45, Park75 or Delta 88 is in order. Thanks!

David Root · Post by **David Root** » Thu Nov 25, 2010 1:34 am

I'm glad the PT worked out. Was that 550 CT or 550-0-550? Not quite clear on that, but probably 275-0-275. With 120V wall AC that would be maybe 400VDC with SS rectifier, 380V with a 5AR4.

67supertrem · Post by **67supertrem** » Thu Nov 25, 2010 6:01 am

From the diagram on the PT, it appears the 500v on High Voltage (Red) secondaries? On the CT, AT 300ma DC? If it helps, I can attach a pic of the diagram.

David Root · Post by **David Root** » Thu Nov 25, 2010 11:54 pm

A pic should clear it up. 500-0-500 would be unprecedented at 300mA unless this PT weighs at least 12 lbs, in my estimation. (BF Twin PT is 320-0-320 at 450 mA, weighs 11 lbs).

67supertrem · Post by **67supertrem** » Tue Jan 18, 2011 12:29 am

Finally, here's are the pics of the diagram of the PT. Hopefully, they are clear enough of the diagram. The tranny weight is only 8.5 lbs. I would like to be able to drive a least a pair of KT66 or KT88's.
Thx. ST

Phil_S · Post by **Phil_S** » Tue Jan 18, 2011 1:13 am

Please try again for a clear picture. Make it farther away if you need to , but it needs to be clear. If it is your hand that shakes, make a pile of books or something to rest the camera on.

David Root · Post by **David Root** » Tue Jan 18, 2011 1:21 am

Looks like 550CT at 300mA. Could be wrong, need a clear pic. Model # looks like R-805A. I'll look it up.

ToneMerc · Post by **ToneMerc** » Tue Jan 18, 2011 1:28 am

I agree with David, it's 275-0-275 @ 300mA. The fact that the R-80A series doesn't appear in any Triad catalog, the L shaped mounting bracket and the number of windings makes me believe that it was a special run for someone.

I guessing under load you should see about 365-370V with SS rect.

TM

ToneMerc · Post by **ToneMerc** » Tue Jan 18, 2011 1:29 am

Cliff Schecht · Post by **Cliff Schecht** » Tue Jan 18, 2011 2:33 am

Maybe good.for a Rocket although you might be slightly high on the B+ and would need to adjust the power state cathode resistor accordingly.

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