Features:

• The transmitter board includes: the clock and time generators, the channel amplifiers, the PAM modulator/multiplexer and the line amplifier.

• The receiver includes: the line amplifier/receiver, the synchronism extraction and processing logics, the demultiplexer and the PAM demodulator and the channel output amplifiers/filters.

• The system must be also provided with 4 testing tone "generators in the voice band and with a transmission line simulator, which must include a variable attenuator and an artificial noise variable generator.

  • System capacity: 4 voice channels (340-3400 Hz).

  • Sampling frequency: selectable between values of about 8 kHz (rated value) and 4 kHz

  • Sinusoidal tone generators (340, 680, 1360, 2720 Hz) with separately adjustable amplitudes.

  • The reciprocal phase relationship of the signals of the four generators must be ensured.

• The educational panel must consist of a complete system of time division multiplexing - demultiplexing of PAM (TDM -P AM) technique.

• The system must have the capacity of 4 channels with speech band plus a frame tuning channel

• The equipment must carried out with components of advanced technology and it uses solid state switches and integrated circuits of CMOS type.

• The panel can be integrated with other panels of the same series to serve as educational aid for advanced courses or it can be used alone.

• At this purpose tone generators and a transmission line simulator shall be included allowing significant and complete exercises.

• The panel must consist of two different sections, for the multiplexing/transmission and the demultiplexing/reception of the signals.

• The equipment must included 4 sinusoidal tone generators, each one variable in amplitude, at frequency of2720, 1360, 680, 340 Hz"

"Performs the following exercises:

• Pulse modulation of analogue signals; relationship between sampling frequency and transmission band

• Sampling theorem

• Time multiplexing and TDM signal transmission; coding of the synchronization signals in a  multiple signal

• Receiver synchronization problems; PAM demultiplexing and decoding

• Influence of the imperfect transmission media characteristics on the transmission quality

• Characteristics of the test signal generators and of the input amplifiers

• Study of the transmission timing

• Study of the PAM multiplexer

• Study of the reception timing

• Study of the PAM demultiplexer and of the output amplifiers

• Transmission characteristics of the PAM system in presence of attenuation and noise

• Power supply: + 15 Vdc, 80 mA