Adaptation of Class E amplifier for amateur radio application is very rare due to inherent difficulties in filter design associated with it till release of usdx transceivers. The above compact transmitter uses class E amplification with three BS170 mosfets, a popular approach in usdx final.
What's new is the oscillator...any similarity with the NS40 is not mere coincidence, this oscillator was based on that design. The modifications were made according to the need, so the value of the 220R resistor was selected according to the TX performance, that is, the input current and the output power, the value of the 10R resistor was the same way. I got a great performance since the NS40 pulls about 750mA! How to turn on the CW handler