[BC] Collins 831F2 assistance needed

[Gary Glaenzer]

no, once I changed the tube, the resistor is fine, also ohm-ed the screen cap, no short

I have good (200 mA) cathode current, which varies with exciter output, so I'm getting
drive to the IPA

I cannot, however, 'dip' the Ik with the 'Driver Plate Tuning' control, nor do I have grid
current on the PA

All this points to a coupling problem, but what ?

From: <RichardBJohnson at comcast.net>

>
> The 4CX250 socket has a built in screen bypass capacitor. It is probably shorted. That
> would take out the series resistor.