Telemetry FM/FM Baseband Structure Study. Volume II

摘要

This volume contains the procedures used and data measured as part of a baseband expansion study. In essence, the program consisted of an evaluation of equipment, a study to determine a feasible baseband expansion, and a program of experimentation to evaluate expansion and provide recommendations for systems application. Telemetry equipment representative of that typical in field use was gathered and evaluated to determine if there were any characteristics which would prohibit its use in an FM/FM baseband expanded in frequency to 200 kc. Those parameters which were thought to contribute to total system error were also evaluated. Parameters such as receiver IF-envelope delay variation, transmitter dynamic linearity, tape-recorder harmonic distortion, etc., were measured. Where possible, similar units from different manufacturers were obtained. In order to determine the feasibility of the recommended expansions of the FM/FM basebands, a complete laboratory telemeter was constructed and several basebands were evaluated using specific system tests. The system tests included experimental optimization of the transmitter pre-emphasis, intermodulation, signal-to-noise and system error tests. Determination of the effect of post detection recording, system accuracy, and applicability for pulse modulation were considered as well. (Author)