In article ,
Carter-k8vt wrote:

Let me toss you a minor curve ball: If you were repairing this radio in
its era, you would indeed be looking for a replacement transformer with
approximately a 270-0-270 high voltage secondary winding; this is
because it was designed for 110 volts AC coming out of the socket on
your wall.

How can we be sure it was designed for 110 volts AC coming out of the
socket on the wall? But that is really irrelevant because the schematic
says the voltages were measured with 117 volts AC coming out of the
socket on the wall, not 110 volts AC.

Today, that voltage is 115 to 120 volts or even a bit higher
and using -today's- line voltage with a 270-0-270 winding would give you
a bit more than the 265 volts DC B+ that you are looking for. So, what I
am saying is that you could (should?) look for a transformer with a
220-0-220 or 250-0-250 high voltage winding; i.e. less (than 270-0-270)
is better.

The specifications listed with the schematic say the radio is designed
to operate with voltages coming out of the socket on the wall of 105-120
volts AC, which would seem to cover "today's" voltage of 120 volts.
Unless the OP has a voltage greater than 120 volts AC coming out of the
socket on his wall I would think he should go for a transformer to the
original spec. Also if his line voltage is high, going for a
transformer with a lower voltage high voltage winding is going to do
nothing to bring down the heater voltage to normal. If this is really
an an important issue, what he should do is look for a transformer with
a tapped primary, unfortunately these don't seem to be as common as they
once were when the transformers in some equipment had taps for low and
high line voltage as well as the nominal line voltage.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/