09-20-2020, 06:11 PM
Swapped out all tubes one by one again, even trying metal tubes where available all to no change. Then I took some voltage readings today.
1.) 5X4 I get 410VAC across pins 3 & 5 (plates), and 358 DC across pins 7 & 8. Schematic calls for 325 V
2.) 6N6's I get 310 on pin 3, and 325 on pin 4. Show be 280 & 290 respectively
3.) 6C5 Phase Changer I get 174 on pin 3 and 8 on pin 8. Should be 165 and 12 respectively
4.) 6C5 2nd AF I get 182 on pin 3 and 8 on pin 8. Should be 155 and 12 respectively
5.) 6Q7 1st AF I get 172 on pin 3. Should be 110
6.) 6J7 AFC I get 214 on pin 3, 111 on pin 4, and 3 on pin 8. Should be 190, 90, and 4.25 respectively
7.) 6C5 OSC I get 81 on pin 3. Should be 90
8.) 6K7 IF I get 283 on pin 3, 84 on pin 4, 1.2 on pin 5 and 7.2 on pin 8. Should be 255, 110, 4.25, 4.25
9.) 6K7 RF I get 281 on pin 3, 83 on pin 4, 1 on pin 5 and 9.7 on pin 8. Should be 255, 110, 7, 7
10.) 6L7 translator I get 281 on pin 3, 84 pin 4, 0 on pin 5, and 9.7 on pin 8. Should be 255, 110, 7, 7
Voltages are running a bit high in general, and none on pin 5's of the 6K7 RF and 6L7 tubes. I can hear the contacts arcing under the chassis when the set is first turned on. The flash tuning light flickers on and off for about 10-15 seconds then it settles down. Need to try to figure out how to get those contacts apart and see why no voltage appears on pin 5.
1.) 5X4 I get 410VAC across pins 3 & 5 (plates), and 358 DC across pins 7 & 8. Schematic calls for 325 V
2.) 6N6's I get 310 on pin 3, and 325 on pin 4. Show be 280 & 290 respectively
3.) 6C5 Phase Changer I get 174 on pin 3 and 8 on pin 8. Should be 165 and 12 respectively
4.) 6C5 2nd AF I get 182 on pin 3 and 8 on pin 8. Should be 155 and 12 respectively
5.) 6Q7 1st AF I get 172 on pin 3. Should be 110
6.) 6J7 AFC I get 214 on pin 3, 111 on pin 4, and 3 on pin 8. Should be 190, 90, and 4.25 respectively
7.) 6C5 OSC I get 81 on pin 3. Should be 90
8.) 6K7 IF I get 283 on pin 3, 84 on pin 4, 1.2 on pin 5 and 7.2 on pin 8. Should be 255, 110, 4.25, 4.25
9.) 6K7 RF I get 281 on pin 3, 83 on pin 4, 1 on pin 5 and 9.7 on pin 8. Should be 255, 110, 7, 7
10.) 6L7 translator I get 281 on pin 3, 84 pin 4, 0 on pin 5, and 9.7 on pin 8. Should be 255, 110, 7, 7
Voltages are running a bit high in general, and none on pin 5's of the 6K7 RF and 6L7 tubes. I can hear the contacts arcing under the chassis when the set is first turned on. The flash tuning light flickers on and off for about 10-15 seconds then it settles down. Need to try to figure out how to get those contacts apart and see why no voltage appears on pin 5.
Greg V.
West Bend, WI
Member WARCI.org
