Seb, Tony:
I'm guessing that we've been getting this waveform from various 9ax, 8xa and similar VICs built by this and other groups for some time now. Now where to?
My observations show that by adjusting the resistance to ground at the negative choke and plate it appears to only reduce ringing voltages yet has no discernable effect on gas production. For example, my ringing voltages PTP are 2000v with anything over 80k ohm and can be drawn down to 100v ptp ringing with zero resistance to ground via a 100k pot.
kb