Panels made in metal case with bench support and the electrical scheme on the front panel.
The board carries out a complete frequency division multiplexer/demultiplexer system for two voice channels.

Theoretical Recalls:

1. FDM Transmission
2. Modulation Contents
3. Single Side Band (SSB) Systems
4. Demodulation
5. General Diagram of FDM Equipments

Technical Features:
The voice signals (340-3400 Hz) of the two channels are translated in frequency by means of modulators operating with carrier generators included in the board. A line driver preceded by the channel filters transmits the composite signal. The receiver, included in the same board, separates the bands of the two channels and demodulates the relevant signals by restoring the original signals back to the voice band. The system includes the automatic gain control in the receiving section, based on the control of the level of a 64 kHz pilot signal sent during transmission. The board also includes three test tone generators, a transmission media simulator with adjustable attenuator and artificial noise generator. Capacity: two channels with voice band Tone generators: sinusoidal at 500, 1000, 2000 Hz Pilot tone: 64 kHz Power supply: +15 Vdc, 300 mA and -15 Vdc, 50 mA With this panel it must be possible to perform the following exercises: Functional study of the panel Study of the input amplifiers and of the balanced modulators Study of the channel filters, Study of the SSB demodulator, Study of the system global response, Study of the automatic gain control system, Noise.