Some “seriously beginner grade” questions regarding resistors

[Helmholtz]

[QUOTE=Enzo;n911941]
Yep, what I usually suggest in the case of the PI grids is just measure from, grid to cathode, instead of to ground. The difference will be a volt or so and they already measured the cathode voltage, so subtract from that. The meter has very little effect on that. QUOTE]

The easiest way to determine grid to ground voltage in an LTPI is measuring the voltage at the bottom of the cathode bias resistor. Grid to cathode voltage (bias) is the voltage drop across the cathode bias resistor.
This applies as long as there is no DC fault current in the grid circuit.

[Gtr0]

You said it yourself in post #33
"I would guess that it is working in conjunction with the 500k pot to operate as a grid leak resistor? as well as with capacitance of v2a to form a low pass? and I suppose other things as well... ??"

Cool... good to know at least I have a chance of understanding it :-) - Thanks!