This weekend I found some time to work on a small QRP transmitter for the minimal art contest. It is based on my 40m transmitter I described here earlier. This is my prototype build on a PCB in ugly construction style sitting next to the spy morse key:
The little transmitter can easily produce 5 Watts ouput with a 12 Volts power supply. In fact I had to add a power limiting resistor in order to keep the output within the QRP limit. Without the additional resistor it would produce more than 10 Watts at 12 Volts and would need only 8Volts in order to reach the 5 Watts limit. I used in total 15 parts including the power limiting resistor and two blocking capacitors. I do not count some 10 MOhm resistors that I have used as support points for my ugly construction.
Here is the current schematic. I will do some simulations and see if I can do some further optimizations: