A very simple FM transmitter circuit can be designed using MC2833 integrated circuit, designed for cordless telephone and FM communication equipment. It includes a microphone amplifier, voltage controlled oscillator and two auxiliary transistors. The final output frequency is generated by frequency multiplication within the MC2833 IC. The RF outpu
t buffer (Pin 14) and Q2 transistor are used as a frequency tripler and doubler, respectively, in the 76 and 144 MHz transmitters. Power output is 9 + 10 dBm for 50 MHz and 76 MHz transmitters, and 9 + 5. 0 dBm for the 144 MHz transmitter at VCC = 8. 0 V. Power output drops with lower VCC.