Snagov (5–6 IC)

The Snagov with integrated circuits is a black-and-white television set made by Electronica in Bucharest, with a 47 cm screen [1].

The stationary sets with 5 or 6 integrated circuits were rated quality class II [1]. Their six linear integrated circuits were: TDA440 (video-sound IF, synchronous demodulator, AGC and video preamplifier), TAA661 (second sound IF and FM demodulator), TBA790 K (audio preamplifier and output), TBA950 (line and frame sync processor), TDA1170 (frame oscillator and output) and TAA550 (stabiliser for the varicap supply) [1]. Because of supply problems and the low reliability of some IC types, some modules (sync processor, frame sweep) were transistorised, giving sets with 5 or 4 integrated circuits [1].

Electronica reached the top level of black-and-white television technology in 1976, when it began making modular sets with integrated circuits, transistorised horizontal sweep (BU205) and a built-in voltage stabiliser [1]. From 1973 IPRS, the Polytechnic Institute and Electronica worked on linear integrated circuits for television: a sync processor (TBA950), a video-sound IF processor with synchronous demodulator (TDA440), an FM demodulator (TBA120 or TAA661), an audio amplifier (TBA790 or TBA810), a vertical sweep circuit (TDA1170) and a 33 V stabiliser for the varicap tuning voltage (TAA550) [1]. The first prototype, designed by chief engineer Eugen Statnic, was ready on 30 June 1974, with a flat, square-cornered AW-61 picture tube from the Pipera factory; its “zero series” in the spring of 1976 verified all the integrated circuits developed and made experimentally at IPRS [1]. Each plug-in module could be fitted with integrated circuits or transistors, as supplies allowed [1].

With this design Electronica became fully competitive abroad: exports rose from 20,000–30,000 sets a year in 1970–1976 to 100,000–150,000 in 1979–1980 and 150,000–200,000 in 1981–1985; more than 200,000 sets with four integrated circuits went to China alone in 1980–1983 [1]. Assembly time fell from 8 hours per set in 1970 (Miraj) to 4 hours in 1980, against 3 hours at Grundig [1]. The models were named Olt (transportable, 44 cm), Snagov (47 cm), Sirius (51 cm), Diamant (61 cm) and Lux (65 cm), followed by three digits: the first gave the channel selector type (1 – VHF, 2 – VHF/UHF), the second the number of integrated circuits (6, 5 or 4) and the third the model [1].

Other models of the same group: Olt, Sirius (5–6 IC), Diamant (5–6 IC), Lux (5–6 IC).

According to the memoirs of Electronica’s chief design engineer, the prototype television set with six integrated circuits was approved in October 1974 [2]. It had a transistorised varicap channel selector for the OIRT standard, horizontal sweep with a BU 105 transistor and a 20 kV line transformer (the memoirs give BU 105, the chapter on Electronica BU205), vertical sweep first with audio-frequency integrated circuits and then with the TDA1170, and a modular design that could take either transistor or integrated-circuit modules [2]. Power consumption fell from 165 W to 85 W, assembly time from 8 to 4 hours per set, and the mean time between failures rose from 750 to 2,500 hours [2]. Electronica’s TV exports to the West grew from 130,000 sets in 1969–1976 to 511,000 in 1977–1981 and 1,338,000 in 1982–1987 [2].

In the source table, video sensitivity is given for 6 V rms on the picture-tube cathode, the signal-to-noise ratio on the sound path, and the selectivity values are, in order, the rejection of the own sound carrier and of signals below and above the picture carrier (and, where given, of the IF and the image frequency); the audio response is at −3 dB [1].