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This variable frequency oscillator was found in an old American documentation. Transistors allow more modern equivalents and coil data are found next to the diagram for several frequency bands.
This short-range FM transceiver uses a headset to listen. We found the circuit in a Japanese...
This Popular Electronics circuit can be found in various versions on this site and in this...
This 80's circuit, suggested in Texas Insrtruments documentation, uses a Hall effect sensor. The...