06-27-2021, 10:41 PM
Success!
Thank you so much Terry, Rod, and Brenda. You were right, Brenda, it had been a few years since I had to do the OSC test with a second radio and did it backwards.
I had previously tested resistors R4 and R5 (50K and 30K respectively). R4 read 52K and R5 read 33K so I left them in. But tonight before trying to inject a signal I decided to replace those two resistors, along with C7 (with a 100 pf) and C8 (with a 27 pf....I didn't have a 25 pf on hand). After replacing those 4 components I turned the set on and checked voltages. I now had the correct plate voltage on the 6J5 and pin 5 read -5.3 instead of nothing. So I slowly began tuning and....the stations came in as they should! I still need to do an alignment but already the set plays strong across the dial. I haven't checked the other bands yet but will do that tomorrow. I feel pretty confident they will receive as well.
Apparently one or both of the two mica's had gone south, thus losing the connection to the OSC coil.
Thank you so much Terry, Rod, and Brenda. You were right, Brenda, it had been a few years since I had to do the OSC test with a second radio and did it backwards.
I had previously tested resistors R4 and R5 (50K and 30K respectively). R4 read 52K and R5 read 33K so I left them in. But tonight before trying to inject a signal I decided to replace those two resistors, along with C7 (with a 100 pf) and C8 (with a 27 pf....I didn't have a 25 pf on hand). After replacing those 4 components I turned the set on and checked voltages. I now had the correct plate voltage on the 6J5 and pin 5 read -5.3 instead of nothing. So I slowly began tuning and....the stations came in as they should! I still need to do an alignment but already the set plays strong across the dial. I haven't checked the other bands yet but will do that tomorrow. I feel pretty confident they will receive as well.
Apparently one or both of the two mica's had gone south, thus losing the connection to the OSC coil.
Greg V.
West Bend, WI
Member WARCI.org