US Naval Radio Transmit Facility Dixon
For most of the 20th Century, the San Francisco area had a strong US Navy presence -- the very first permanent installation on the West Coast being Mare Island in the 1850s. The cessation of Soviet Cold War hostilities -- and the ongoing political hostilities by enemies from within -- local Congressional beasts like Ron Dellums, Barbara Boxer, Nancy Pelosi caused the US Navy to flee the Bay Area starting in the 1990s. Today, about the only major presence the USN has in the Bay Area is the US Naval Radio Transmitter Facility, Dixon (callsign NPG).

Naval Radio communications on the West Coast of the United States dates back to 1904, with a radio facility located on Mare Island. By 1917, due to high-power output and multiple frequencies in use, the Navy created a separate receive annex and communication center on Yerba Buena Island in San Francisco Bay. In 1920, the communications center moved to the 3rd floor of the Federal Building in downtown San Francisco, and as the US Naval communications mission continued to expand, a larger HF receive facility was established a few miles South -- Naval Radio Station South San Francisco (located where the Genentech Corporate campus is now). In 1942, the NAVRADSTA SSF receiver facility closed and was replaced by a new facility in a more rural area with more space and fewer sources of local radio interference -- Skaggs Island. Wartime communications needs in the 1940s, and continued expansion of Naval facilities in the San Francisco Bay area, caused the establishment of Naval Radio Station (Transmit) Dixon, located on a large parcel of land about 10 miles SE of the community of Dixon, California. The several hundred acre facility housed numerous high-power, high frequency radio transmitters, as well as a housing & recreation facility for assigned personnel & their families on the SW section of the complex.

In 1952, due to Cold-War era concerns (San Francisco would be targeted by the Soviets), NAVCOMMSTA San Francisco relocated from the SF Federal Building to new facilities aboard a Navy depot on Rough & Ready Island, and eventually became known as US Naval Communications Station Stockton, continuing to use the NPG callsign on some circuits.

The Mare Island transmitter site was decommissioned sometime in the 1960s or early 1970s. Throughout the 1970s and 1980s, NAVCOMMSTA Stockton would have utilized their Dixon transmit annex to communicate with US Navy and allied warships and aircraft operating in the Eastern Pacific area, using single-sideband clear and encrypted voice as well as ciphered radioteletype (CRATT) modes for Fleet Broadcast. Similar transmit stations on Hawaii and Chollas Heights (San Diego) were also operational, with NRTF Chollas Heights & it's receiver facility at Imperial Beach closing in the mid-1990s.

Due to both budget constraints as well as advances in technology (satellite communications, and networking), NAVCOMMSTA Stockton was disestablished circa 1997, and Naval Radio Transmitter Facility Dixon, by now operated by a civilian contractor firm, is the last major vestige of a proud US Navy history in the San Francisco Bay area. Rome Research Corporation, a subsidiary of PAR Technology Corp, has had the operations and maintenance contract since the Navy crew and their families left, while the former Navy housing area is now an "migrant housing center" operated by Yolo County. Microwave radio relay stations atop Mt Diablo and Mt Vaca, built for the Army in the 1950s and once used to relay traffic between 6th Army HQ at the Presidio of San Francisco & the Army's West Coast (HF) Radio Relay Facility near Davis were turned-over to the US Navy in the 1970s to link NRTF Dixon with NAVCOMMSTA Stockton and other Naval facilities in the Bay area. The Mt Vaca structure was sold to a private venture, and the Mt Diablo facility, no longer used by the Navy, was turned-over to another federal agency.

I have visited this site once in the early 1990s, and numerous times between 2002-2009. Upon my last visit, I sat in my car just outside the compound and searched the HF spectrum, finding the site transmitting KG-84 enciphered data on about 12 different HF channels, plus broadcasting on a VLF frequency.

Since the early 2000s, this facility has hosted the USAF "West Coast" High-Frequency Global Communications System (HF-GCS) network transmit site, remotely controlled from a facility at Andrews AFB Maryland.

NRTF Dixon is an amazing sight/site for any radio-buff to see, because it is located adjacent to two other major HF antenna farms -- the former Voice of America Dxon Relay Station, and AT&T High-Seas Radio 'KMI' transmit facility. I have separate photos sets of those facilities, as well as for NAVCOMMSTA Stockton.

I hope to scan and upload my early 1990s-era images of NRTF Dixon soon.

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