A Confession

[Electronic M]

Originally Posted by Hagstar

Thanks Tom. I believe you but how does this prevent arcs? Hair of the dog principle ? Bleeder resistor value principle I grasp....
EDIT - I see you must mean it would prevent arcing from the focus pin by providing a safe super high resistance path.

John H.

Without the resistor the focus pin is at ~25KV and can arc to anything grounded within ~2-3"....With the resistor to ground that pin is at the designed value of ~4-6KV and probably won't arc more half an inch... That pin is meant to be the output of a voltage divider...Take away the bottom half of the divider and things go WAY out of design spec.