In January 1970, Congress was informed that NSGA Hanza was assigned the mission for providing support to the U.S. Navy which consists of high frequency direction finding (HFDF), Communication Security (COMSEC) and other Naval Security Group functions. Congress was told that the activity receives assistance in services and facilities from nearby Torii Station. The site occupied 132 acres by the 1970s.

The AN/FRD-10 CDAA was developed by the Naval Research Laboratory (NRL), with the assistance of the Department of Electrical Engineering at the University of Illinois, under Project Clarinet Bullseye. The Navy awarded the contract to produce and install the world-wide network of stations to ITT Federal Services in 1959. Eighteen operational systems were built; fourteen were maintained by the Naval Security Group (NSG), two by the National Security Agency (NSA), and two by the Canadian Forces. They replaced AN/GRD-6 HFDF systems at most places (although not at NSGA Kami Seya).  The AN/FRD-10 sites in the Pacific, in addition to Hanza, were Guam, Wahiawa in Hawaii, Imperial Beach and Skaggs Island in California, Marietta in Washington, and Adak in Alaska, as well as Masset in British Columbia, Canada.


The AN/FRD-10 at Hanza was the first to become operational. An installation crew consisting of about eight communications technicians destined for Hanza was trained at the ITT factory at Nutley, New Jersey, which was completed on April 13, 1962.  An RCA technical representative also participated in the training. Operations began at Hanza in October 1962. The Clarinet Bullseye sub-systems were then installed and became operational in early 1963.

The AN/FRD-10 system consisted of two concentric circles of vertically-polarized antenna elements, one covering the low part of the HF spectrum (with longer wavelengths) and the other the high part of the HF spectrum, together with two tall reflector screens to improve the signal amplitude (or gain), laid on a ground mat of copper wire mesh covered by about three inches of gravel. It was called an outward-looking array because the high band antenna ring for monitoring shorter wavelengths was located on the outside (as compared to the Air Force/Army AN/FLR-9, where the high-band ring was on the inside). Each antenna element was linked by RG-85 A/U 75 ohm very low loss coaxial cables, which also connected them with the Operations Building located at the center of the array. Rotating goniometers (one for each band) in the Operations Building determined the direction of arrival of the target signal and displayed it on a cathode ray tube. The Operations Building also contained AN/FRA-54 recorder/analysis systems and banks of R-390 radio receivers.

R-390 Radio Receiver

The AN/FRD-10 CDAA at Hanza was slightly smaller than its successors. The low band sub-system (which covered from 2 to 8 MHz, or two octaves of frequencies) consisted of 36 folded dipole antennas, about 65 feet in height, spaced 10 degrees of azimuth apart (whereas subsequent AN/FRD-10 low band sub-systems had 40 dipoles). The high band array (8-30 MHz) consisted of 100 sleeve monopole antenna elements, about eight meters high, spaced at 3.6 degrees intervals of azimuth (whereas subsequent FRD-10s typically had 120 monopoles).

Source: Nautilus Institute for Security and Sustainability, 23 December 2015