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
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
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
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 .
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
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
1942 - Receiving equipment and functions moved from Mare Island to Skaggs Island
1945 - SSB transmitters installed for Washington and Honolulu circuits
1961 - The five 450' towers and the LF transmitters were removed - about 60 HF
transmitters remained in operation.
1965 - Operations moved to Dixon CA