AM Press/Exchange, issue 63, August 1988, page 12.

Coverage tests were scheduled between August and October 1988
by the Space and Naval Warfare Systems Command (SPAWAR) under
contract with Astron Corp. Transmit locations were to be
Bumpass, VA and Carroll Island, MD. Primary frequencies were to
be 185 KHz and 175 KHz. Power output was to be 1 KW. The
antenna was to be a triangle-shaped loop antenna 65 feet high at
the apex and 400 feet long at the base, made of #0 guage Litz
wire, capacitively tuned. Reports from longwave listeners were
requested, a SPAWAR Washington, DC address was given. Several
amateurs were reported to have been involved in the tests: AK4R,
N4QYC, N4SBY, W4ZW and W4NEZ