Mare Island Transmitter Site - US Navy Radio NPG

Naval Radio History of 12th Naval District (San Francisco) - by LT George Todd, USN RET - pdf

1904 - Radio Station (Call sign TG, later NPH) established with Slaby-Arco transmitter at the HILL location
1912 - 5 KW quenched spark gap transmitter installed
1915 - 30 KW arc transmitter installed - call sign changed to NPG since Yerba Buena became the control station

Equipped with one 30 KW arc transmitter adjusted for these wavelengths : 4000 ( calling) , 4800 (working) , 6000, 8100, and 12000 meters ; and one 5 KW, 500 cycle quenched gap spark transmitter, adjusted for : 600 (commercial), 952 (calling), and 2400 (working) meters . Both transmitters were operated by remote control from the Yerba Buena station. Separate antennas were installed for the arc and spark transmitters . Receiving apparatus was also installed at the Mare Island station. There were four private landline circuits between Yerba Buena and Mare Island; three telegraph circuits for arc control, spark control and message circuit ; and one telephone circuit used as an order circuit for operation of apparatus and adjustment of wavelengths, etc . That circuit was bridged into the offices of the Pacific Coast Communication Superintendent at Yerba Buena and the Radio Officer at Mare Island . The arc set at Mare Island was used for communication with San Diego, Lents, Oregon, Puget Sound, Cordova and Great Lakes, Illinois. Traffic with Puget Sound, Cordova and Great Lakes was by schedule only. Traffic with San Diego was on a continuous call basis . The spark transmitter at Mare Island was used to communicate with Farallon Island, Eureka, Marshfield, Oregon (night only), North Head (night only), and with ships equipped with spark sets . Time signals were transmitted simultaneously daily at noon and 10 PM, 120th meridian time, on both arc and spark transmitters on 4800 and 2400 meters. This was accomplished by the Mare Island station switching control of both transmitters direct on the Western Union wire which was connected to the Naval Observatory at Mare Island . The station broadcast local weather conditions, storm warnings and hydrographic information in accordance with Radio Regulations .

1920 - Construction of new Power House, Operating Building, and three 450' towers at HIPOWER location
1920 - 100 KW Arc transmitter moved from Tuckerton NJ, 40 KW arc transmitter moved from South San Francisco
1922 - additional 100 KW Arc transmitter and two additional 450' towers installed
1942 - Receiving equipment and functions moved from Mare Island to Skaggs Island
1945 - SSB transmitters installed for Washington and Honolulu circuits (multi-channel RATT)
1961 - The five 450' towers and the LF transmitters were removed - about 60 HF transmitters remained in operation.
1965 - Operations moved to Dixon CA
March 1949
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January 1940
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1921 view from antenna tower
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100kw towers - 1920
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Yuerba Buena circa 1917-20
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Building 505 HF Transmitters - photos and plans - main link -

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