"flipper" wrote in message
...
I just received a pair of SE OPTs that were claimed to be from a
stereo console with 6BQ5 outputs. So far so good as that's precisely
what I wanted to build.

Problem is, when I put 120.7 AC on the primary I get 1.9VAC out for a
ratio of 63.5/1, which comes to roughly 32k/8 ohms, or 16k/4 ohms, and
from what little I know of 6BQ5 characteristics that doesn't make any
sense to me. I mean, 8K would be good but a console with 2 ohm
speakers?

Physically, the core is gapped with (actual core) dimensions of 2.25
inch wide by 1.74 inch high and .75 thick. Mounting is 2.75 centers
with 10A15-10 marked on the frame. Primary and secondary, 4 wires
total. No taps.

Does anyone have information, or an educated guess, on what these
transformers may really be or what I'm missing about 6BQ5s with such a
high OPT impendence?

Hmmm.

Well, if these are really rotten output transformers, which are down 3 dB at
60 Hz, your calculations would be way off, no?

Measure them again at 400 or 1000 Hz. Connect them backwards to the output
of a small amp fed with1 kHz and report back. I'll bet the calculated ratio
is different at 1 kHz than it is a 60 Hz.

Also advise your test equipment. Many old VTVMs and VOMs are horribly
inaccurate on the low VAC ranges. They may also be bad at frequencies other
than 60 Hz.