4) Salvage a broken piece of test equipment like a frequency counter or multimeter. If the tubes light up, swap out the control circuitry for an Arduino or your

4) Salvage a broken piece of test equipment like a frequency counter or multimeter. If the tubes light up, swap out the control circuitry for an Arduino or your microcontroller of choice. It’ll already have the high voltage DC supply and maybe even some 74141 decoder/driver chips. (Just don’t spend a lot of money on something that deserves to be restored.)