Further consideration of the power supply kit voltage (about 200VDC out) as supplied verses the modification to 390 volts using a bridge circuit:

Studying the 6V6 tube data we see that 390 volts is a little hot for the tube. It also pushes the limits of the capacitor voltages as supplied in the kit. The bleeder resistor runs warmer than with the lower voltage. We have concluded that we will not change nor advocate modifications to the power supply kit as now in production.

It is further noted that the 6V6 transmitter will produce 2 or 3 watts out with the current power supply. This seems like plenty of power for some fun qrp work. We will soon introduce the companion receiver and the voltage range is just right for that.

Another advantage of the 6V6 tube and other similar types is that they are still in production due to their popularity in audio amplifiers.

If you read this and would like to buy our power supply kit as it is now manufactured, email me at nn8g@arrl.net and I will send you an invoice for purchase of the power supply with $10.00 off coupon.  

73 Glenn NN8G