Im working on a new QRP transmitter based on the 74HCT240 octal buffer, the circuit has been described on many places, even in ARRLs books. http://www.qsl.net/5z4ft/74hc240qrp.html I am getting about 150mW on 20m, and about 225mW on 40m, but i was hoping for a bit more. People have reportedly gotten approx 500mW out of these circuits. I am using the HCT i stead of the HC(problem finding the HC model), but thats the only difference i could fint. I have left some room on the board for a low pass filter, and a microprocessor to control the transmitter.