The following circuit as an intermediary between the telephone line and connect the phone, and then all conversations can be heard on an FM radio.
The complete training program to build the transmitter is provided which includes the introduction of parts used and full description with pictures, switch and important points is that using it even novices in the field of electricity and electronics are easily can this circuit interesting not fix.
PCB The circuit also been put to work to build the circuit easier, but the circuit is simple and can be easily board with holes in the circuit shut myself on the board perforated closed and fully answered.
a range of about 500 meters to easily hear.