The high voltage supply for the vacuum tube transmitter needs to be low noise in the 40 meter band, efficient for battery operation and able to supply at least 200 Vdc from a 12 volt battery. The current draw is expected to be about 50 mA, a supply with at least 75 mA capability would be preferred. I expected that the load on the supply would change during keying of the transmitter. This means the supply needs to maintain a steady output voltage under changing loads for a