Credit for this circuit gos to: www.circuitstoday.com/medium-power-fm-transmitter-circuit. I simply did the layouts, breadboard and stripboard for you in these pages.This is the circuit diagram of a moderate power adjustable FM transmitter circuit employing two transistors.The voice signals picked by the microphone is amplified by transistor Q1. The second transistor Q2 is an oscillator operating in the 88 to 108 FM band.The output of Q1 is fed to the base of Q2. The tank circuit is comprised of components L1 and C6, a parallel circuit that determines the frequency of the signal, and can be varied over the FM band by adjusting C6. The capacitor C7 couples the FM signal to the antenna. Antenna is from 14 to 18 inches long. Use a small flex insulated wire. The circuit is for the 88 to 108 MHz band. Reduce C6 to around 5 to 10 pf for the VHF band.