Model 782 Tunable PSK Subcarrier Generator (2U Chassis)
The Model 782 Tunable PSK Subcarrier Generator BPSK modulates a data stream at subcarrier frequencies up to 10 MHz. Local front panel control is provided through a high contrast vacuum-florescent display and keypad. English language menu selections allow rapid unit configuration and operation. Test automation is supported through an RS232 control port that allows remote setup by computer.
The Model 782 performs both coherent and non-coherent modulation. In coherent modulation applications, the Model 782 provides a TTL or RS-422 clock that is a submultiple of the subcarrier frequency. The data source, using this clock, provides a coherent modulation input to the Model 782. The modulated output signal is selectable between a sine wave and a square wave and can be adjusted in amplitude and offset up to ±10 volts. Data and clock is input to the unit as either TTL or RS-422. The data can be NRZ- (L,M,S) or BIØ-(L,M,S). The input data is converted to NRZ-L. This NRZ-L can be differentially encoded to NRZ-M or S. The subcarrier is then modulated by the differentially encoded data. The modulating data is also output to the rear panel allowing the Model 782 to function as both a Data encoder and decoder.
The unit can also serve as a general purpose frequency synthesizer for rates of 10 Hz to 10 MHz. The frequency output is selectable between sine and square waves.