12-26-2013, 10:48 AM
Herb;
No, I do not currently have a variac. I may get one eventually if I find one with a reasonable price. I have used an incandescent lamp in series with power before to evaluate whether a unit has serious problems in its power supply. I will be looking for a variac at local swap meets. I ordered some replacement caps from www.tubesandmore.com including coupling caps and another electrolytic with a higher voltage rating. Tubes and more seems to have more electrolytics for tube circuits at a reasonable price than others including Digikey and Mouser. Their prices for coupling caps with a 630V rating are quite decent too.
They have a Hammond 125E push-pull audio transformer for $40.77 with multiple speaker output taps that I believe is closer to the OEM Philco transformer, so after I get all the other issues taken care of I may order one of those to replace the Stancor replacement transformer that is in the radio now.
I might build up an AC input voltage bucking adapter to reduce the nominal 120-125VAC power seen at our house these days. These older radios were not designed for modern higher voltage situations. I found a good chassis mount AC input fuse holder available at Radio Shack. Since I already have an existing hole in the rear of the chassis where I removed the phono input, I may just add a fuse holder there for the AC input circuit. I definitely want to protect all the hard work that has gone into this radio. IMO lack of an AC input fuse is a serious design error.
Joe
KC5LY
No, I do not currently have a variac. I may get one eventually if I find one with a reasonable price. I have used an incandescent lamp in series with power before to evaluate whether a unit has serious problems in its power supply. I will be looking for a variac at local swap meets. I ordered some replacement caps from www.tubesandmore.com including coupling caps and another electrolytic with a higher voltage rating. Tubes and more seems to have more electrolytics for tube circuits at a reasonable price than others including Digikey and Mouser. Their prices for coupling caps with a 630V rating are quite decent too.
They have a Hammond 125E push-pull audio transformer for $40.77 with multiple speaker output taps that I believe is closer to the OEM Philco transformer, so after I get all the other issues taken care of I may order one of those to replace the Stancor replacement transformer that is in the radio now.
I might build up an AC input voltage bucking adapter to reduce the nominal 120-125VAC power seen at our house these days. These older radios were not designed for modern higher voltage situations. I found a good chassis mount AC input fuse holder available at Radio Shack. Since I already have an existing hole in the rear of the chassis where I removed the phono input, I may just add a fuse holder there for the AC input circuit. I definitely want to protect all the hard work that has gone into this radio. IMO lack of an AC input fuse is a serious design error.
Joe
KC5LY
