Originally Posted by MOSFETapocalypse
This only happens when this resistor is in circuit? How high does the current rise? Whats the plate voltage? Bias fluctuations can sometimes be attributed leaky grid cap's leaking in DC from the preceding stage.
If this is only happening while setup for biasing, assuming all connections are good, You may want to try to use a .1 ohm resistor, i typically use this value especially if this resistor has to be permanently installed.
Thanks Travis, never thought of a smaller resistor. Are .1 ohm's easy to find and do they come in high wattage packages?
The plate Voltage is 410V and the amp is brand new condition barely used.
I checked out all the electrolytic caps with my ESR meter, all 100%.
The bias will keep rising to dangerous territory.
This only happens with the tester because the V on pin 2 stays steady whereas it drops with the bias tester.