Modify Selection
- Equipment, tools, and parts:
- Medium frequency communications systems
- Document types:
- Contract reports
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Results 1 - 8 of 8
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9/1/1986 - Contract reportsThis report describes the creation of an efficient method to determine if command, control, communication, and monitoring (3cm) equipment in coal, metal, and nonmetal mines is susceptible to radio frequency interference (RFI) from the medium-frequency (...
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9/1/1984 - Contract reports, Open File ReportsThis report deals with information regarding a new Medium Frequency (MF) Wireless Communication System for underground mines. This new telecommunication system works on low loss electromagnetic wave propagation modes which allow it to provide quality ra...
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1/1/1983 - Contract reportsAn underground medium frequency radio communications system has been developed and demonstrated in both coal and metal/non metal mines. The principal advantage of the system are its low cost, ease of installation and the ability to provide radio communi...
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7/1/1979 - Contract reports, Open File ReportsThis report describes a complete system design for medium frequency ( MF) wireless radio systems for use in coal mines. The emphasis is on AC mines where no trolley wire exists and, for which, conventional trolley phone communications cannot be used. Th...
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10/1/1978 - Contract reportsThis document describes the decision factors that bear on the selection of the modulation process for the wireless underground medium frequency (MF) communication system.
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9/1/1978 - Contract reportsThis report covers antenna design, analysis, and development work suited for use with a wireless radio communication system operating at medium frequency. The work includes the test and evaluation of prototype vehicular antennas developed during the pro...
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9/1/1977 - Contract reportsAn investigation was made of the feasibility of developing compact transmit antennas and/or other means to efficiently couple VLF to MF band radio energy between portable wireless communication units in coal mines. The completely wireless communication ...
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9/1/1977 - Contract reportsThis report describes magnetic field measurements in the Helvetia Coal Co. Lucene No. 8 Mine for purposes of deriving a mapping of the magnetic field strength covering the major haulageways which contain conductors.
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Content source: National Institute for Occupational Safety and Health, Mining Program