Working on a homebrew 20m CW transceiver and considering different PA topologies. A class E power amplifier is potentially incredibly efficient (theoretically up to 99%!) but is difficult to get right.

Has anyone successfully implemented Class E in a QRP design? What's been your experience with component tolerances and real-world efficiency? Worth the complexity over a simple Class C stage for 5W output?

Built a Class E stage for my 40m rig last year. The efficiency is amazing when tuned right, but the component tolerances are critical. One bad inductor and you're back to 60% efficiency. For QRP work, I'd stick with proven Class C designs unless you enjoy lots of tweaking.

The transmitter is based on Steve Weber's design because it's perfect and is used in some form by many QRP CW rigs. It gives me between 4-6 watts output on all bands Sometimes simple is better - proven designs get you on the air faster!

Class E is fascinating but for portable work I want reliability over maximum efficiency. 37dBm...TX Draw:800mA shows you can get good results with straightforward designs. My 2N3553 PA gives me 5W at 65% efficiency and never fails in the field.