The BA1404 integrated circuit (not very easy to obtain) consists of a complete stereo FM transmitter, applying the signals directly to an antenna for a low power mode. For greater power, the signal from pin 7 can be applied to an RF amplifier stage. The coil consists of 4 turns of wire 28 in a shape with an adjustable core of 0.5 cm. Capacitors must be ceramic and the supply must be made with one or two small batteries. The crystal determines the stereo multiplex operation of the circuit. The circuit is from the BA1404 manual itself.
| Clique na imagem para ampliar |
