Hi guys. I build a FM transmitter based on the ba1404 chip. The problem arises because this chip need a 38Khz crystal for produce a subcarrier signal for the stereo transmition, but that crystal is hard to find. To solve it i programed a PIC16f84 to generate the 38 Khz signal and, depending of what crystal use for the PIC, i could reproduce the 38Khz fecuency more or less exactly. (For example wuth a PIC runing on a 4MHZ crystal a can generate a 38,4 Khz signal). What accurate such signal have to do?
Thanks, and scuse my english. Cheers.