The pilot detector output is designed as an open collector output, therefore an external pull up resistor is needed. To force the decoder to `MONO` Pin 19 has to be clamped to a voltage below 0. 8V. visit page.
This circuit is a circuit diagram is included in the RF circuit. FM Transmitter circuit diagram using the IC BH1417. Where the integrated circuit design from RHOM which includes many features in one small package. He came with pre-emphasis, limiter so that music can be transmitted in the same audio level, stereo encoder for stereo transmission, visit page.