When testing using a variac set at 12vac, shouldn't I be reading a dc voltage at the plates and screens (pins 3 & 4)? And since I am not, can I suspect a bad trans?
2 posters
M-125 Question
5/35- Posts : 15
Join date : 2014-03-01
Location : Friday Harbor WA
Bob Latino- Admin
- Posts : 3277
Join date : 2008-11-26
Location : Massachusetts
5/35 wrote: When testing using a variac set at 12vac, shouldn't I be reading a dc voltage at the plates and screens (pins 3 & 4)? And since I am not, can I suspect a bad trans?
Do you mean a variac set to 120 VAC ? and not 12 VAC ? With the amp on with all tubes inserted, check the DC voltage from pin #8 of the rectifier tube socket to chassis ground .. If you get no DC voltage then the rectifier is not working and you will also get no DC voltage on the plates and screens.
Bob
5/35- Posts : 15
Join date : 2014-03-01
Location : Friday Harbor WA
Thanks Bob,
A zero is just a place holder..... Right?
I'll check as you describe once I return from short road trip.
A zero is just a place holder..... Right?
I'll check as you describe once I return from short road trip.
Similar topics
