RTF-MF

The RTF-MF is a fixed radiotelephone (base station) for networks with mobile and portable sets, made by IEMI in Bucharest [1]. It was made in several type variants (1 MF-S/SD, 1 MF-S A, 3 MF-S/SD, 4 MF-S/SD); IEMI also made 57 control units for the 1 MF-S, 23,812 control units for the 4 MF-S and 67,612 accessories [1]. IEMI made radiotelephones under a licence bought in 1968 from the Swedish firm SRA (Svenska Radio Aktiebolaget), later modernised by IEMI itself; they were used in industry, on the railways, in rescue services, agriculture, transport, construction, by the police and the fire brigade [1].

IEMI’s production table lists the transceiver units of each variant: 11,005 RTF-1MF-S (1975–1985), 1,136 RTF-1MF-S-A (1975 and 1977), 976 RTF-3MF-S (1976–1985) and 9,917 RTF-4MF-S (1973–1985), with 23,181 rectifiers and buffer rectifiers [2]. The RTF-4MF central unit (F10730) cost 7,500 lei and an antenna 1,400 lei (prices set in 1982) [3].

Annex III.2.15 says the fixed set gave two-way links with mobile and portable sets, forming a radio network. It consisted of a control unit with loudspeaker and microphone, for local or remote control, which selected the carrier frequency, could monitor two carriers alternately with the automatic channel changer, set the volume in steps (with a first position for selective calling with an external alarm) and keyed the transmitter when a permanently installed microphone was used, and of a transceiver unit identical to that of the mobile RTM-MF. It was fully transistorised; the prospectus describes the 146–174 MHz version, simplex (programmable for semi-duplex), with 6 channels, 2.5 W of audio into 16 Ω and mains supplies of 110–240 V [4].