My FM Wireless Microphone has been a very popular project with beginners and experienced constructors alike. It has been used inside guitars and as the basis of a remote control system. I do however, receive many requests for a higher powered circuit and better microphone sensitivity.
Construction is quite simple.
L1 is 3.25 turns in spiral form and is an integral part of the PCB foil pattern. The final stage is a BC557 PNP general purpose device. If you use different devices then you should select the 1M0 resistor for 5-volts DC at the collector of the the first transistor. Select the 47K resistor for 3 - 4 volts on the collector of the third transistor. Here is the V5 component overlay drawing.