PAM-FM GROUND STATION (G-A AND VIBRATION) VOLUME II. THEORY OF OPERATION AND MAINTENANCE (FIRST REVISION)

The purpose of the PAM-FM Ground Station is to receive, process, record, and present for on-line, real-time readout PAM-FM telemetered information from a vehicle. Certain Ground Station installations are capable of reproducing the recorded information for delayed readout on visual-display equipment. The Ground Station consists of a Receiver, Base Band Unit, Demultiplexer, Digitizer Datrac, Record and Reproduce Electronics, a Magnetic Tape Recorder, Sample and Hold Output circuitry, and in the case of Vibration operation, a Visual Display Unit Visicorder. The input to the receiver of the Ground Station is a PAM-FM signal. The receiver output is an amplitude-modulated pulse train proportional to the pulse train delivered to the vehicle transmitter by the vehicle multiplexer. This pulse train is amplified, band-limited, and delivered to the Datrac for digitization. Each pulse of the pulse train, including the sync intervals, is digitized into a nine-bit binary word and delivered to the Magnetic Tape Recorder for parallel recording in Non-Return-to- Zero NRZ form. The pulse train is also delivered to the Demultiplexer for separation into individual channels corresponding to the channels of the vehicle multiplexer. The information from the Demultiplexer is used for real-time readout on visual display equipment.