The Story of an Old Timer: Out of Room (part 3)

The wooden transmitter building burned to the ground on November 6, 1940.

After the fire Congress allocated $230K for a new brick station located three miles south on U.S. Department of Agriculture experimental farm - but still called Beltsville - but some referred to it as Greenbelt.

It was up and operating by January 1943. Stability was improved to 2 x 10⁸ by burying three 100 kHz quartz crystals in a concrete vault 25 feet below ground.

In February 1944 a 2.5 MHz transmission was added. In December of 1946  25, 30 and 35 MHz transmissions were added and the Radio Section was renamed the Central Radio Propagation Laboratory (CRPL).

All signals were closely monitored back at the Bureau and at the USNO which allowed the two entities to synchronize their clocks and signals. This later led to the decision on atomic clock definition of the second ... cooperation with NPL.