UTC transformer ID?

[hodad]

I'm looking at UTC part # HD-639. The partial catalog I have on my computer doesn't list it. At this point I'd be happy just to know what the HD indicates.

Thanks
Tom

 

[CJ]

Is it a transformer? Choke? Filter?
I don't see it in the 60-61 catalog, but will check my other catalogs.
They probably did a lot of private labeling so we may never find it.
What size is it?
A-10 style? LS series? HA-100X series?

 

[al_p]

it's not in the '55 or '70 catalogue either.

 

[hodad]

These are smallish & unshielded--there's a half dozen of them in this thing called a Grass Instruments S8 stimulator that I picked up surplus for the case & the 11 Amperex 12AU7A's it was sporting. Unfortunately, the thing is built in such a way that I haven't yet managed to figure out where the leads run so that I might take a measurement or two. Oh, well. They're probably useless for audio anyway.

Tom