Frequency-Shift Transmission of SPR Signals Over Local and Transcontinental Communication Links

Abstract

The material included in this report covers the initial field testing of the Navy Synchronous Polarity Reversal Facsimile Security System (SPR), using frequency-shift radio transmitting facilities. It was found that high speed (1000 baud rate) operation was successful over any radio link that was free of multipath Transmission, but that in the presence of average multipath on long-haul circuits, only slow speed (333-1/3 baud rate) operation gave satisfactory results. Difficulty was also experienced at high speed with phase distortion on both long and short land lines.

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Document Details

Document Type
Technical Report
Publication Date
Sep 25, 1947
Accession Number
AD1204372

Entities

People

  • Bert Fisk
  • C. L. Spencer

Organizations

  • United States Naval Research Laboratory

Tags

Readers

  • Radio communications and signal processing.
  • Software Engineering
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).