Harris HT30 & 35 FM transmitter display power supply
Retrofit power supply mounted on display PC board
In the HT30 and HT35, Harris used a Vacuum Fluorescent Display (VFD) that is driven by a power supply in a potted module. Those modules were long ago discontinued by their manufacturer, and Harris has not had any stock for years. The guts of that potted module were not magic, and we figured out what was needed to generate the +39V for the anode and the 5.4V pk-pk 10 kHz squarewave for the filament, and made our own! Ours is not potted, so it’s not as pretty as the original, but it works just fine.