The small experimental transmitter of the figure can be used as a protable microphone or in spying. With L1 formed by 4 wire turns 26 or 24 in the form of 1 cm in diameter without core and CV a trimmer of 4-40 pF or close to that the circuit can be adjusted to operate in the FM range. In this case the antenna will be a piece of hard wire 15 to 40 cm. The power may come from common batteries and all capacitors must be ceramic, minus C2 which is an electrolytic for 3 V or more.
