12-12-2015, 09:14 AM
(12-09-2015, 09:47 PM)murf Wrote: Hi Terry,Hi Murf,
Checked voltages on both 6L6 tubes and are as follows.
Tube 1
Pin 2 6.5 ac
Pin 3 220v
Pin 4 244v
Pin 5 -7.4v
Pin 7 checks 0 volts ac(should be 6.3)
Tube 2
Pin 2 6.5v ac
Pin 3 243v
Pin 4 244v
Tested both 6L6 tubes also,
Tube 1 checked 4000 (mut cond = 5000)
Tube 2 checked 3500
Pin 5 -31.6v
Pin 7 checks 0 volts(should be 6.3)
High voltage a little low
6.3 ac missing on pins 7
Irregular voltage on pins 5
Tubes check low on my hickok tester.
What do you make of this?
murf
Well, The mismatch between the two control grids is a problem. According to the RCA tube manual it should be close to -22vdc. Would check the 10K resistors in series with the grids and two secondary winding of the driver transformer, you may find one is open.
Terry