History
ICRET (Întreprinderea de Construcții și Reparații Echipamente de Telecomunicații, the Telecommunications Equipment Construction and Repair Enterprise) was the industrial unit of the posts and telecommunications directorate of the Ministry of Transport and Telecommunications (MTTc), set up on 1 January 1967 to make small series of complex telecommunications equipment not made elsewhere in Romania [1].
History
In 1968–1973 it worked in the Vitan post office building, in 1973–1985 in its own building on Izvor Street, demolished for the House of the People, and in 1985–2000 mainly on Orhideelor Street [1]. It appears from 1991 as a joint-stock company; no economic report of it has been published since 1996 [1]. In its first 20 years it put more than 600 products into production, saving imports worth about US$100 million; its output grew almost 40-fold and its staff sevenfold [1].
Products
It began with television translators (low-power rebroadcast transmitters) and the repair of manual exchanges and public telephones; by 1987 it was making the third generation of translators, more than 500 of which were installed – fully transistorised units of 1.5, 1, 5 and 10 W for bands I–III, and 100 W units with a main and a standby unit and a TH 328 output tube – which switched on about 5 s after an input signal of at least 100 µV appeared and off 45–60 s after it disappeared [1]. In 1970–1987 it made 59 FM broadcast transmitters of 6 kW for the OIRT band (66–73 MHz), which carried Romania’s FM programmes until 2003; from December 1978 its diplexers combined two transmitters on one antenna (three at Herăstrău from April 1983), in 1986 it introduced automatic mono–stereo switching, and on 29 December 1983 the first Romanian 6 kW transmitter in the Western band (100.1 MHz, at the Litoral station) went on air [1]. Its modular 2 × 3 kW FM transmitter could use any frequency in the OIRT and CCIR bands without imported quartz crystals; after 1991 it made small transmitters (25–150 W) for private radio stations [1]. It also built the transmitting antennas for broadcasting from the 1970s, two high-power industrial RF generators and, in 1973–1990, reconditioned power tubes for transmitters, industrial generators and army radars – several hundred GI-5B tubes, which lasted about three times longer than new ones [1].
Its radio relays included lines of 24–60 analogue and 30 digital channels at 400 MHz, a 130-channel relay at 2 GHz and, from 1975, the 1,800-channel relay for 6–8 GHz made to GTE (Italy) documentation, with the CRT 142 transmitter-receiver and the CMF 18 modulator-demodulator; with the ICPTTc design institute it then made a 2 GHz digital relay and designed 960-channel analogue relays for 4–6 GHz [1]. Microwave components designed at ICE, such as the CS-030 circulator, went to ICRET for its radio relays [2]. For telephony it made 30-channel PCM terminal and line equipment, an 8 Mbit/s multiplex for 120 channels, ringing and tone generators for automatic exchanges, cable pressurisation and power equipment [1].
From 1980 it introduced equipment with the 8080 microprocessor: electronic registers replacing the electromechanical registers of Rotary exchanges (about 1,300 installed in Bucharest in four years), the SV 32 subscriber traffic supervisor (1983), the TX 8 terminal (1985), a remote terminal for supervising PCM systems and a system for automatic calls at a set time (1986) [1]. For the railways it made, from 1975, about 3,000 INDUSI speed control installations and, from 1976, about 4,000 safety and vigilance devices, fitted to all CFR locomotives and metro trains [1].