BA1404 FM Stereo modulator
Using BA1404 can be designed a very simple and useful fm stereo modulator electronic project . This BA1404 fm stereo modulator device works in FM broadcast band ( 75- 108MHz) and require few external common components .
The BA1404 fm stereo modulator Ic contains all parts needed to design an simple high efficiency stereo transmitter circuit . This IC contains a stereo modulator that creates stereo composites signals ,an FM modulator that creates FM signals and a RF amplifier .
The fm stereo transmitter develops composite signals made up of a main(L+R) signal and sub(L-R) signal and a pilot (19KHz) signal using a 38KHz crystal oscillators.
The RF amplifier transmits the stereo encoded signals and is also a buffer for FM modulator .
For this FM stereo transmitter circuit you’ll need a DC power supply that can provide an output voltage between 1.5 an 3 volts .
The L1 coil must have 3 turns of 0.5mm wire on a 5 mm core .
Antenna used in this transmitter can be an common telescopic antenna or a 60-80 mm long Cu wire .