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AM transmitter with TL072Шема
This small transmitter uses just one IC. The TL072 is a dual op amp. One of the op amps has been connected
as high frequency oscillator. The other op amp has been connected as modulator. The buffer is pretty simple and
is made with just one capacitor and one resistor - what causes some little (neglectable) frequency modulation in the oscillator. The sound is pretty good and the transmitter is astonishing frequency stable. The transmission frequency goes from 680 to 900Khz. The transmitter has a range of 5...10cm. With the hf amp that is shown in the circuit diagramm the transmission range can bee improoved up to 2m. The circuit diagramm can be found here