We have an EMI amplifier (IFI406)?with 24 4cx250s in a TWA. one of them has a short between G1 and cathode. It comes and goes with heat and when it happens the plate supply shuts down. Anybody have an idea of a safe hipot test voltage. It is not a hard short so need a way to isolate it. Only want to remove the tubes once. This thing is 1 KW out 10 KHz to 220 MHz and idles at about 7 KW resting.??
