Lighting Up a Mystery CRT with a Vintage Power Supply

The Hewlett-Packard 6516A could source up to 3000 volts at 6 milliamperes with 1 volt resolution. Voltage was set by four decade thumbwheel switches on the front panel. Output was floating (isolated from ground), so multiple supplies could be connected in series to obtain higher voltages.

Plus, building a homebrew high voltage probe.