04-08-2016, 12:56 PM
Hi Terry
I removed one tube at a time, starting at the front end and moving thru the stages. Turn off, next tube, turn on, repeat. Variac held AC input voltage at 100V. Every tube removal had the same result. Plenty of hum. I included both 41 tubes also, one at a time, and got plenty-o-hum.
OK, time to break out my Tek 475 o'scope to check the B+ and B- supplies.
New 7C6 and 7A6 should be arriving in the next couple of days.
Thanks
Mike
I removed one tube at a time, starting at the front end and moving thru the stages. Turn off, next tube, turn on, repeat. Variac held AC input voltage at 100V. Every tube removal had the same result. Plenty of hum. I included both 41 tubes also, one at a time, and got plenty-o-hum.
OK, time to break out my Tek 475 o'scope to check the B+ and B- supplies.
New 7C6 and 7A6 should be arriving in the next couple of days.
Thanks
Mike
