The station's mission began in 1905 at what is now Truman Annex, when it was called the Naval Wireless Telegraph Station. Back in 1915 it broadcast time signals just like NAA in Washington, NAT in New Orleans and NPH in San Francisco among others.
NAR, was a link in a chain of Wireless Telegraph Stations in what was then referred to as the "Coastal Signal Service" of the US Navy. That chain extended from Cape Elizabeth, ME, to New Orleans. It further included wireless stations at Guantanamo Bay, Cuba; San Juan, PR and after 1910, even one in Panama.
Following World War I, the military downsized many installations. The air station and submarine base were closed
and its personnel released. Many buildings on Trumbo Point were demolished. But a small Navy force stayed on to continue maintaining that wireless station at the Naval Station in Truman
But in the 1960s as the cold war ramped up, the base expanded once again. At it's peak the site employed 19 officers, 268 enlisted personnel and 31 civilians. In 1965 the Navy even acquired the 640 acres of land on Saddlebunch Key to build another transmitter site. But the cold war cooled off and the radio functions became civilian-led and operated by contractors. More here.
In 2011 the Navy began the process of closing the long-running radio
communications center. Improvements to high-frequency broadcasting
require fewer stations. The station was officially
decommissioned on Sept. 21 2012. The station signed off in Morse code. It had been 107 years since the station first signed on.