The radio direction finder was a special antenna that determined the direction of radio transmissions. It was invented by an Italian team, but Bureau of Standards researchers patented an improved design. Built in 1916, it served as a prototype for the U.S. Navy and was used widely to pinpoint the positions of enemy forces during WWI. By the mid-1920s, many civilian vessels were outfitted with the "radio compass" as it came to be known. Today NIST performs calibrations and develops the standards and measurement techniques and instrumentation needed for high performance antennas.

Francis Dunmore tested a sample type of radio direction finder on the roof
of the Bureau of Standards Radio Laboratory   -from NIST
Photographic Collection, Radio Direction Finder



W.G. Wade received signals from a coil (or loop) antenna
- mainly used for direction finding - at a Kennsington Maryland
field station in 1919   -from NIST Photographic Collection,
Radio Direction Finder


BACK