1.- Introduction:
Main features of the FM transmitter-receiver board.
2.- FM Modulation:
Analysis of the reactor modulator.
Analysis of the varactor modulator.

3.- Frequency Demodulation Techniques:
Analysis of the Untuned Resonant Circuit.
Analysis of the Quadratic Detector.
Analysis of the Foster-Seeley Detector.
Analysis of the Ratio Detector.
Analysis of the Closed-Loop Phase Detector Circuit.
4.- Adjustment of Tuning Circuits.
5.- Error Generator.

The module consists of a single board for studying FM communications, including transmission and reception, and also noise effects existing in communication.

The board includes two frequency modulators and five discriminator circuits.

Alternatively it is possible to modulate the amplitude of the FM signal using an external noise input signal.

Transmitter:
Modulator circuits: Reactor and Varactor.
Output frequency: 455 KHz.
Frequency range of the audio oscillator: 300 Hz. to 3.4 KHz.

Receiver:
Demodulator circuits: Tuner resonator, square-law
detector, ratio discriminator, synchronous detector, and a
Foster-Seeley discriminator.
Low-pass filter/Amplifiers.
Filter cutoff frequency: 3.4 KHz.
Eight commuter switches.
Testing points for measurements using an oscilloscope.