07-26-2013, 02:41 PM
My list of string diagrams doesn't include the PT-91. Nor can I find a picture of it on the Philco Radio Gallery. Is it a portable, like the PT-88? I have a 41-81T, which looks similar to the PT-88, and has the knobs in the same place. If there is any similarity I'd be glad to open it up and take a look at the dial string.
If your PT-91 is very different from the 41-81T, then obviously my suggestion won't work.
Alternatively, you could ask Chuck Schwark if he has a Philco service package for this model. It will almost certainly include a string diagram. Chuck charges a small fee for these documents, but they are well worth it. http://www.philcorepairbench.com/schematics.htm
If your PT-91 is very different from the 41-81T, then obviously my suggestion won't work.
Alternatively, you could ask Chuck Schwark if he has a Philco service package for this model. It will almost certainly include a string diagram. Chuck charges a small fee for these documents, but they are well worth it. http://www.philcorepairbench.com/schematics.htm
John Honeycutt