Basically, it’s piece of rock and it’s an insulator. Its schematic symbol is shown in Figure SB1. Varactor (varicap) circuit symbol How does a varactor diode work? To form the PN junction that makes a ...

LC-tank circuit portion Varactor (or “varicap”) diodes are used primarily in radio-frequency (RF) circuits to provide a capacitance that can be varied by changing the applied voltage. These ...

The circuit uses two integrated circuits from Maxim. IC1 a MAX4467, is an amplifier raising the microphone signal to a level suitable for frequency modulation (FM). IC2 is a voltage-controlled ...