AN/FRD-10
The AN/FRD-10 is a United States Navy circularly disposed antenna array (CDAA), built at a number of locations during the cold war for high frequency radio direction finding (HF/DF) and signals intelligence. In the Joint Electronics Type Designation System, FRD stands for fixed ground, radio, direction finding. 14 sites were originally constructed as a part of the "Classic Bullseye" program. Two AN/FRD-10 systems were later installed in Canada. AN/FRD-10 systems were originally constructed in the early 1960s, but after the dissolution of the Soviet Union, the systems began to be shut down and demolished. The Naval Security Group operated and maintained the U.S. Navy AN/FRD-10 systems. The system had several nicknames including Fred-10 and Elephant or Dinosaur cages. As of 2015, none of the US Navy AN/FRD-10 sites are extant, but the two Canadian sites remain in service. The AN/FLR-9 was a system with a similar design and function, but operated by the US Air Force and Army.
| Circularly Disposed Antenna Array (CDAA) | |
AN/FRD-10, Wahiawa, Hawaii | |
| Country of origin | United States |
|---|---|
| Introduced | 1961 |
| Type | Circularly disposed antenna array (CDAA) |
| Frequency | Low Band 2-9 MHz High Band 9-32 MHz |
| Inner Array Antenna radius | 393.5 feet (119.9 m) |
| Inner Array Reflector radius | 366 feet (112 m) |
| Outer Array Antenna radius | 436.75 feet (133.12 m) 431.75 feet (131.60 m) at 4 sites |
| Outer Array Reflector radius | 423.5 feet (129.1 m) |
| Range | 3,200 nautical miles (5,900 km) |
| Antenna Cost (1970) | $800,000 to $900,000 ($7.06 million today) |
| Electronics Cost (1970) | $20 million ($157 million today) |