Some of the relevant sections include:
- Fun with Crystal Oscillators, Part 1, Part 2 and Part 3
- More Fun With Crystal Oscillators: Amplifying RF
- A Mighty Simple Shortwave Transmitter
- So You Want to Be a Shortwave Pirate
- An Altoids Tin Low Pass Filter For Shortwave Transmitters
There are some great general interest posts on Mike's blog, too, so click on over and enjoy Mike's hard work.
Simple, safe experimental circuits designed to get you hooked on RF - enjoy the addiction!