F-1641

The F-1641 is a manual military field telephone exchange of medium capacity, which also switches four-wire circuits and channels, made by Electromagnetica in Bucharest [1]. The manual field exchanges designed by ICSITA with CCSITTc were the small F-1612 and F-1613, for 10 subscribers, and the medium F-1640 and F-1641, for 30, 60, 90 or 120 subscribers [1].

Section V.2.2 calls it a semi-automatic exchange, a modernised F-1640 with LEDs, new switches, advanced protection of subscribers, lines and channels and a modular construction [3]. The annex describes a family of semi-automatic field exchanges for 30, 60, 90 and 120 subscribers, for stationary and vehicle signal centres, switching two- and four-wire lines of the local-battery, central-battery, automatic-exchange and long-distance (multiplexed) types [2]. It was built from plug-in units – a 20-subscriber distribution unit, 10-subscriber units, switching, operator and power units and two keyboards – and the operator set up the connections from the keyboards, over 15 four-wire cords; the 30-line version had 10 local-battery, 10 long-distance, 7 local/central-battery and 3 automatic-exchange subscribers [2]. It was approved in 1985, and in 1988 Electromagnetica made ten lots; a 60-line exchange was fitted in the F-2013 vehicle and another on the Defence Minister’s train [2].