Universal Combined Radio Relay and Tropospheric Scatter Equipment [AN/FRC-( )] — IRE Transactions on Communications Systems

September 1961, pp. 292-297: the design philosophy of the AN/FRC family - a “matrix of least-common building-block equipments” that could be composed into line-of-sight or troposcatter subsystems for the Air Force’s AIRCOM plan. The equipment lineage behind the North Atlantic Radio System. Cited from the journal (DOI above); the PDF is commercial IEEE property and is not hosted here.