This small FM transmitter was found in a Radio Electronics magazine in 1991. The magazine no longer exists, but the circuit can be assembled with equivalent transistors such as BF494 for Q2 and BC548 for Q1, although 2N2222 are still common. The coil is formed by 2 + 2 turns of 24 or 26 thread without core and without shape with 1 cm in diameter. The smaller capacitors must be ceramic, and the microphone is a 2-terminal electret. The range will be in the order of a few dozen or even hundreds of meters. C6 should be 4.75 to 5.6 pF and C5 is a common trimmer.
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