[Mark H]

This is my first time posting and am grateful to be part of this forum ! I recently started working on a Philco 91 that I had acquired several years ago and am trying to figure out what is a mystery to me? I am told that Ron is the Philco expert, so I am very curious to see what he says ! A little background...When I opened this radio I discovered that two sections of the original BC resistor (900/2700 ohm) had apparently become very hot and at sometime had been replaced with two ohmite type ceramic resistors...one of them had deteriorated as well. The only other work that I could see done was two older dry electolytic caps had been wired in to replace the two originals. Anyway, I got the schematic and all the info I could from several sites and began to restore the radio to original specs. I replaced all the caps, rewound one coil etc etc. When i slowly powered the radio up I could not receive stations well....I took tube voltage readings and noticed the SG voltage on the RF/44-Det/36-IF/44 were way out of spec...155 volts instead of 50/80/85...I also noticed that the new BC resistor I had assembled out of 25 watt ohmites was getting pretty hot in the 2.7K ohm section....after several posts on another site, another guy with a Philco 91 opened up his set and found the same voltages ? The tubes are only rated for 90 volts max on the SG, so how could this be ? I tried replacing the 900 ohm section with a 5K ohm resistor and the SG voltages dropped to around 77 volts and the radio plays beautifully now all across the dial. All the info I have says the BC resistor was as I found it (900/2700/95/205). I am happy with the repair. I am just wondering how Philco built this radio the way it did ? I don't see how the Screen Grids on those tubes could be what they call for with that 900 ohm resistor ? Were there lot's of problems with Philco 91's ? Anyway, I am curious to see what others have to say.

Thanks for any input !

Mark H