Simple Am Radio Transmitter Circuit. For example if you get 2 volts then slightly re tune so you get 1 95 and leave it. Connect ground of the circuit to your earth connection for crystal radio testing or your water pipe.
To boost the reception coil the wire in a circle and use zip ties or electrical tape to keep the coil from unraveling. Use a small diameter insulated wire such as a 20 or 22 gauge and cut it to a length of at least 15 or 20 feet 4 6 or 6 1 m. Rotate the trimmer capacitor and tune maximum reading on the high side of the frequency you need that is the best tune point.
This circuit is designed with limited power output to match the fcc regulations and still produces enough amplitude modulation of voice in the medium wave band to satisfy your personal needs.
A phono oscillator is a simple short range am band transmitter that was typically used to send the signal from a phonograph to a nearby radio eliminating the need for an amplifier and speaker. Inductor l1 is used as a broadcast loopstick antenna coil whereas capacitor c1 is set for tuning. Connect ground of the circuit to your earth connection for crystal radio testing or your water pipe. This version uses only one transistor and can be tuned to any desired frequency near the top of the am band.
