2020-03-29 AM Osc + Modulation + Buffer

This is from Electronics Illustrated Projects 1968. It shows crystal sockets, but instead a RF coil may be used and its value will be about 220 microhenrys. And C1 and C2 will have to be changed to bring the frequency down to the AM band.

The germanium transistors are no longer available so silicon transistors should be used. PNP or else change the circuit for NPN. Like 2N3906 or 2N3904. Or BC557 or BC547.

The audio oscillator is a phase shift oscillator, which typically has a clipped sine wave. The S2 should be a single pole, double throw with one pole going to the existing R10 and the other pole going to a jack for external modulation. So this can be used as an AM band transmitter with an antenna no longer than 3 meters.

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