09-07-2014, 07:03 PM
in looking at the nostalgair papers, there is a note about a change in the production runs of the model 80.
cap 37 was indeed a 10uF cap, and in a newer production run it was changed to a .015uF non polarized cap.
cap 32 was also eliminated in this run.
i believe i have the version with the .015uF cap because there was a big metal box mounted to the front panel that had three leads (two caps and a common ground im assuming) one lead is part 25 and one is 37 if i am thinking correctly.
i am thinking about adding part #32 back in, as it cant hurt and im guessing was eliminated as a cost saving measure.
just so we are all on the same page, my philco 80 is at this point correct with this schematic:
http://www.philcoradio.com/tech/images/80.jpg
please, if any of you see anything in this schematic that i should change, let me know!
i didnt get a chance to mess with the radio last night, but i will be working on it later tonight so im open to any suggestions or things to try.
i still havent measured the resistance from the center tap to chassis ground (should be about 330 ohms in my case) and im wondering if this was shorted, would that cause this hum?
thanks for all the help so far.
LC
cap 37 was indeed a 10uF cap, and in a newer production run it was changed to a .015uF non polarized cap.
cap 32 was also eliminated in this run.
i believe i have the version with the .015uF cap because there was a big metal box mounted to the front panel that had three leads (two caps and a common ground im assuming) one lead is part 25 and one is 37 if i am thinking correctly.
i am thinking about adding part #32 back in, as it cant hurt and im guessing was eliminated as a cost saving measure.
just so we are all on the same page, my philco 80 is at this point correct with this schematic:
http://www.philcoradio.com/tech/images/80.jpg
please, if any of you see anything in this schematic that i should change, let me know!
i didnt get a chance to mess with the radio last night, but i will be working on it later tonight so im open to any suggestions or things to try.
i still havent measured the resistance from the center tap to chassis ground (should be about 330 ohms in my case) and im wondering if this was shorted, would that cause this hum?
thanks for all the help so far.
LC