AN/UCC-4

The AN/UCC-4, or UCC-4, was a solid state frequency division multiplexer manufactured by Lenkurt in 1969. It was used by the United States Air Force to provide voice frequency communication to the Department of Defense.

Description
The UCC-4 comprised 12 voice frequency channels in the range of 300 to 3000 hertz, which made up a group. Five groups formed a supergroup and ten supergroups formed a mastergroup, thus making it expandable to 600 voice frequency channels or more, and compatible with the contemporary L-carrier of AT&T Long Lines.

The UCC-4 was connected to a microwave radio that operated in the band of 4.4 to 5 GHz gigahertz, which was transmitted via either line-of-sight or tropospheric scatter to the next communications station.

Repair and maintenance
The technology and maintenance of the UCC-4 was taught to airman of the career field 304X0 at Keesler Air Force Base, Mississippi.The UCC-4 was unique because all of the modules were hermetically sealed. The technician maintaining the piece of equipment merely had to take out the faulty module and replace it with a functional one, and this was the start of what became known as black box maintenance. Before the development of this technology, technicians would be required to troubleshoot and repair the faulty unit. The black box technique of maintenance meant the equipment was put back on line quickly, and the faulty module was sent to a depot where it was repaired by a team of technicians.

Usage
One unit that used the UCC-4 multiplexer was the Electron Maintenance Workcenter in 2045 Communication Group, based at Andrews Air Force Base, Maryland. The Electron Maintenance Workcenter comprised Radio Relay Equipment Repairmen, who later became known as Wideband Maintenance Equipment Repairmen who maintained the UCC-4, teletype equipment, radio equipment, modems, and other ancillary pieces of equipment to support the communications effort.

Associated links

 * 1960s Communication
 * 39th Signal Battalion