Old Style Simple Transmitters

QST Sep. 2013. In Technical Correspondence, there is a short article "Fun With Old Style Simple Transmitters" by Larry, WR1B. The basic idea is to build the 1946 style transmitter in current technologies. It uses the 74AC540 logic chip to put out 1W of power (with 6V). Clever.

Homebrew 50W linear amp for QRP transmitter

I found an interesting article on building a linear amp with MOSFETs: Homebrew Challenge II Co-Winner, The Lowest Cost Entry (David W. Cripe, NM0S), QST October 2010.

It uses two IRF520 MOSFETs that operate in Class E mode. The technique called Envelope Elimination and Restoration (EER) is used to make this a linear amplifier. As MOSFETs are relatively cheap and the efficiency of Class E amplifiers are very good (around 90%), this is something I am interested in and I would want to experiment with sometime.