150-300 milliWatt 88-108MHz FM Transmitter by Harry Lythall

The transmitter is not Harry's first. In fact, Harry Lythall is pretty famous on the internet for his radio broadcasting circuit designs.

This transmitter is a wideband circuit design that outputs 150-300 milliWatt (mW) depending on DC voltage supply. According to the page, 9 volts delivers 150mW and 12.5 volts delivers 300mW, with a VARICAP modulation technique, and the possibility to add a synthesizer (thus making it a PLL [Phase Locked Loop]).

If you have some kit building experience and you want to build your own FM transmitter, or an oscillator (exciter) for a powerful amplifier, then this is exactly what you should need.