This small transmitter for the medium wave range (MW) was found in a 1980 publication. Its signals can be heard in medium wave radios at up to 10 m, depending on the caprice with which the reader performs the assembly. Of course, the circuit must be set to "pick up" at a point where there is no station transmitting. The coil consists of 10 meters of 28 or 30 AWG enameling wire that has a 0.8 or 1 cm diameter and approximately 6 cm long ferrite rod. The trimmer connected in parallel with the coil serves to adjust its frequency, which should be between 550 kHz and 1,600 kHz, and as an antenna, a piece of wire about 2 meters long or a telescopic antenna can be used. The microphone used is a common speaker, 4 or 8 ohms, with a 470 nF capacitor in parallel.
