Edward Knobloch wrote:

Gene Marcus wrote:

I am repairing my B&W 51SB-B Single Sideband Generator and need the
following audio transformer:

Primary 20,000 ohms single plate 10MA DC
Secondary 500 ohms
B&W part # T-826


Hi,

Looking at the 51SB schematic, is the T-201 input transformer
for the antivox circuit the same as one you need?
If so, move that transformer over and use any generic
20,000 Ohm to 600 Ohm transformer for the antivox input.
(You don't need precisely 500 Ohms in the antivox circuit).
The antivox input circuit has no d.c. current at all
in the high Z winding, so any small transformer
will work there.

73,
Ed Knobloch

Thanks for the tip Ed, but I have used T-201 to replace T-204 in the
past. T-202 is bad. When all is said and done, I will probably have to
use the two good original transformers as a matched pair in the output
circuit (T-202 and T-203) to maintain balance.

I don't know why the audio transformers seem to be the weak link in
this rig. The B+ is correct and I'm measuring 4 ma through the
high Z winding, well below the rated 10 ma.

73,

Gene