In this modulator, FM is created by having the intelligence signal cause a change in the transconductance of a JFET, which causes a change in the JFET amplifier's input capacitance, which shifts the resonant frequency of a tank circuit:
A) PLL modulator
B) VCO modulator
C) reactance modulator
D) varactor diode modulator

Question

Quizplus · Accepted Answer

The correct answer is reactance modulator. This type of modulator works by varying the reactance in a circuit, in this case, through changes in a JFET's transconductance affecting the input capacitance, which then alters the resonant frequency of a tank circuit to create frequency modulation (FM).

In This Modulator, FM Is Created by Having the Intelligence