Fm Modulator Circuit

Posted on Nov 21, 2012

The FM modulator is built with a Motorola MC1648P oscillator. Two varactors, Motorola MV-209, are used to frequency modulate the oscillator. The 5000- potentiometer is used to bias the varactors for best linearity. The output frequency of approximately 100 MHz can be adjusted by changing the value of the inductor. The output frequency can vary as much as 10 MHz on each side. The output level of the modulator is -5 dBm. In this prototype, the varactor bias was 7.5 V for best linearity;

Fm Modulator Circuit
Click here to download the full size of the above Circuit.

but this could be different with other varactors.

Leave Comment

characters left:

New Circuits



Popular Circuits

Count Down Timer with PIC16F84A
3V Water-Level Detector
Potentiometer-Position V/F Converter
Do Oscillation Building Circuit by Your Self!
ADC 207 Flash Converting Schematic Diagram
Data Based IQ Modulator
Refrigerator Alarm Circuit
decoder circuit
Serial To Parallel Converter
colpitts oscillators
VFO/BUFFER circuit
Flasher Circuits
LM Frequency Meter
A common collector amplifier