Inductive or Non-Inductive Cathode Bias Resistor?

[Deke609]

I am just putting together what will hopefully be the last Mouser order for the Kaiju rebuild.  And since I'm going "all out" I figure I'll get some nice Vishay 1%, highly temp stable 1K bias resistors for the 300Bs.  I've gotten into the habit of automatically choosing non-inductive wirewound resistors - figuring that inductance in a resistor is a nuisance best avoided.  But for a cathode bias resistor, where I want a constant current through the resistor to maintain a constant voltage drop, maybe inductive is the way to go?

Any thoughts on that?

cheers and thanks, Derek

[Paul Birkeland]

Inductance in a resistor can be a big problem when you have high frequency signal passing through it and the inductance in the resistor makes the resistor appear to be a much higher impedance value at those high frequencies.  In a cathode biased 300B amp, the cathode resistor has a huge cap across it, so there's nearly no signal current passing through the resistor, so a little inductance isn't problematic.

[Deke609]

Many thanks PB.  That makes sense. I forgot to take into account the role of the cathode resistor bypass cap in maintaining a relatively constant voltage bias.  So I think I'll just stick with non-inductive out of an abundance of caution.

cheers and thanks, Derek