N
N Cook
- Jan 1, 1970
- 0
Was I wasting my time , rather than throwing out some ECC83, a 6V6 and some
EL34 and EL84.? All various degrees of C/H leakage causing
vibration/tinging sensitivity so useless despite useful gain.
All measured 5 to 20 M ohm on C/H insulation test on valve tester.
Decided to power the heaters from a bench ps and try C/H leakage with a 500V
Megger insulation tester.
Increasing the heater volts from normal 6V , for short durations then back
to 6 , and monitoring on the Megger. Eventually taking up to 15V for 1
second , no longer orange glow of course, and vey low C/H Megger resistance.
Now measuring them for the C/H leakage on the valve tester better than 30
meg (maximum measurable on my tester).
EL34 and EL84.? All various degrees of C/H leakage causing
vibration/tinging sensitivity so useless despite useful gain.
All measured 5 to 20 M ohm on C/H insulation test on valve tester.
Decided to power the heaters from a bench ps and try C/H leakage with a 500V
Megger insulation tester.
Increasing the heater volts from normal 6V , for short durations then back
to 6 , and monitoring on the Megger. Eventually taking up to 15V for 1
second , no longer orange glow of course, and vey low C/H Megger resistance.
Now measuring them for the C/H leakage on the valve tester better than 30
meg (maximum measurable on my tester).