One more idea -- the old mass-produced geiger counters now available
cheaply on eBay have very simple HV supply circuits that use minimal
components, and run from 1.5 to 6 or so volts, depending on the model.
They come with a schematic and parts list. Although the parts are just
about all obsolete, you could find modern substitutes that would work.

Roy Lewallen, W7EL

KD7TOG wrote:
Thanks all for the ideas ... I have a couple of potential solutions.

Tony, KD7TOG