>Now, this looks to me like two potential dividers,
>which combine to make one potential divider and
>two "sub-dividers" if that makes any sense. If I
>change the total resistance on one side, the other
>side will be affected and vice versa. So how do I
>pick resistor values for this thing?
 >
>Here's how I simplified/understood it:

Oh setting out to play with the DG7-32 are we?

A variation you may like to consider is the way Electronics Australia did
things when they used a DG7-32 in an oscilloscope they described in a series
of articles back in the 1960s/70s. They used a cathode resistor to the VG1
voltage, so the cathode current dropped enough voltage across the resistor
to generate the required voltage difference between the two electrodes, just
like a normal valve circuit biasing arrangement where the grid is taken to
ground through a resistor, and the cathode also has a resistor that causes
it to be +ve wrt ground. This gave what they described as "automatic
brightness control". Unfortunately the magazines are half way around the
world from me, so I cannot just go and look it up.

This series of articles is how I knew about the DG7-32 and its voltages when
you enquired the other day.

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