Posts: 13,776
Threads: 580
Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
It sounds like someone took some liberties with your radio.
Pin 4 of the 77 is the suppressor grid and should connect to ground.
Pin 5 of the 77 is the cathode and should connect to the top of the oscillator tickler coil per the schematic.
If I were you, I would change the wiring to correspond with the schematic.
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Ron Ramirez
Ferdinand IN
Posts: 194
Threads: 34
Joined: Jul 2016
City: Spring Lake MI
Yes I will thank you Ron.......................
Jim
Spring Lake MI
Posts: 194
Threads: 34
Joined: Jul 2016
City: Spring Lake MI
Resolved the wiring on the #77 tube and it made a world of difference, can receive station across the dial. Will do an alignment, I am getting a lot of whistling and vibration in the speaker on certain frequency's. Hope the alignment will solve that.
Jim
Spring Lake MI
Posts: 194
Threads: 34
Joined: Jul 2016
City: Spring Lake MI
After an alignment I noticed that from about 1000 kHz and lower freq. the reception will work at times or not. Above 1000 kHz does not fail can always receive.
I had a VOM lead connected to chassis with meter on, with the other probe I would touch the #2 pin (plate) of #77 tube and make it (lower freq's) come and go. Also on the OSC coil I could touch pin #5 (to tuner) and it will cut out, touch pin #4 it will cut in, this is all to do with the lower freq's. If I touch pin #1 or pin#2 has no effect (tickler). Touching pin #3 will also make it cut out.
I don't know if this is a tube (#77) problem or the OSC coil or what.
I have a 6200 ohm resistor to ground instead of an 8000 ohm on the tickler coil.
I have rewound the tickler coil on the OCS coil it was open.
Jim
Spring Lake MI
Posts: 194
Threads: 34
Joined: Jul 2016
City: Spring Lake MI
Finally got this guy up and running. As I said it would work on high freq's and some times on lower freq's. I tried bonding all grounds, replace the OSC cathode resistor back to 8.2K no help. Finally I cleaned the 77 tube socket and replaced the 77 tube after cleaning the pin of the tube. WALA it now works, I am one happy camper.
Thanks for the help.
Jim
Spring Lake MI