The circuit shown in the figure can act as a home repeater for AM signals from the output of an audio transmitter. The range depends on the antenna which is a stretched wire with a cover that can be 1 to 20 meters long. The Q1 transistor must be mounted on a heat radiator and all capacitors except C1 are ceramic. The modulation input can come from the audio output of a small audio amplifier. The 1k-ohm potentiometer must be adjusted for greater performance without distortion. The L1 coil is formed by 50 + 50 turns of 26 or 28 AWG wire in a ferrite rod 8 to 10 mm in diameter and 15 to 20 cm in length.
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