FM Phone Transmitter Kit

This kit attaches in series to one of your phone lines. When there is a signal on the line (that is when you pick up the handset) the circuit will transmit the conversation a short distance. In particular it will radiate from the phone line itself. It is a passive device- there is no battery. It uses the signal on the phone line for power. No aerial is needed - it feeds back the RF signal into the phone line which radiates it in the FM band. The frequency of transmission may be adjusted by trimcap.

Note that some countries may ban any electronic device which attaches to the telephone. It is the responsibility of the purchaser to check the legal requirements for the operation of this kit and to obey them.

The kit is constructed on a single-sided printed circuit board (PCB). A computer aided design program was used to design the board.

The kit attaches to ONE of the two phone lines going to your phone. Either of the two lines will do. Cut the phone line. Attach one alligator clip to one cut end and the other alligator clip to the other cut end. Take your phone off the hook and turn on an FM radio at about 93 MHz. It should be very easy to tune into the Fox transmission. Take a portable FM receiver outside and follow the phone line.