10-18-2014, 08:15 PM
(10-18-2014, 07:36 PM)morzh Wrote: Is the grid pulled by 1M where it is supposed to and the oltage is correct on it?
Have you tried to change the tube?
The plate voltage comes from 3uF lytic cap, is the voltage on it good?
You sir, are my hero. I traced back the grid to the bakelite cap 116 near the bottom of the schematic. Turns out I had accidentally switched the two wires running to it. Flipped them around, fired up the radio, and life is good. Volume works as expected. Voltages are in line pretty much across the board (+/- 15v or so). I guess I don't understand these circuits enough to know where to look for problems. Since the voltage was off on the plate, my first instinct was to check the connection to the plate.
The entire band 2 is just a whistling noise, even at the lowest volume. I wonder if that is a symptom of the open coil on band 2 as mentioned earlier in the thread by someone else. Not sure if I want to tackle that or not. It would require dropping the RF chassis again, and figuring out which coil it is. And seeing if I can fix it. The only coil I've ever fixed were the two outer windings on my 60B. And those were easy, simple like 15 turns. This little coils look a little more complex to fix.