Interstage Transformer

[KE6DF]

Since this is turning into mystery transformer day, I have another one.

This is a small interstage transformer from the same BC1E modulator driver deck.

It drives the 845s, from push pull triode connected 6v6s (as far as I can tell from the way the sockets were wired).

It's obviously not the original unit. It's much smaller, and was kind of hanging in a bigger hole by one mounting tab.

Kind of a hambone deal and not something I would expect of a professional broadcast engineer.

It's push pull plates to two grids with a split secondary.

The number is CTC - H5442

It also says Link No. 55535

I figure it's from Chicago transformer co., but that's a guess as there is no logo or company name on it.

I'm wondering if it's a broadcast quality unit.

I don't suppose an interstage to drive AB1 (or A) 845s would have to be big if there is no grid current.

Dave

[KL7OF]

Looks like the ones that gates used......Does it have a stenciled  ID like T-1 or T-5 on the top...?
You know what it is..PP plates to grids w/ split secondary...Would work as an out put tx for an audio amp with pp output and neg feedback....... via the split secondary...

[KE6DF]

No sign of a T transformer number.

It has a small black circular stamped thingy printed on the side.

It's kind of smeared, but it looks like "LA" with a funny L where the bottom of the L extends into the cross line of the A.

It may be nothing.

Dave

[KL7OF]

ART 13-SPEECH AMP INTERSTAGE?

[KE6DF]

Good thought, but no.

I have a couple ART-13s and those are rectangular not cylindrical.

About the right size, though.

The ART-13 interstage transformer is also single plate (6V6) to push pull grids (811s)

This one is push-pull plates to push-pull grids.

[KA2DZT]

Interstage xfmrs usually are a step-up ratio.  Most are 3:1.  It is going to be class A so there is no grid current.  PP plates of triodes like 12AU7 to PP grids of some other class A or AB1 tubes.  Usually you can figure about 10ma in each side of the primary.

The xfmr does look like it was made by Chicago by the CTC.  It is most likely a special as it is not shown in any Chicago catalog I have.

Fred