Enescu S 602 A

The Enescu S 602 A was the first upper-class radio receiver of Romanian design, made by Electronica in Bucharest from 1960 [1]. It was the first Romanian-designed receiver for FM broadcasts on the VHF band, and it also had three short-wave bands and separate tone controls for bass and treble [1]. It was designed by engineer Nona Millea [1].

Frequency modulation had not been used in Romania before, so there was no experience in designing, adjusting or testing FM circuits and no trained staff [1]. Professor Gheorghe Cartianu and lecturer Viniciu Niculescu of the Bucharest Polytechnic gave technical assistance; the production problems of the FM block were largely solved after a team of the works visited France, and were finally settled by engineer Virgil Teodorescu once experience with series production had built up [1].

Together with the transistor Solistor S 595 T, it was one of the two novelties of 1960 shown in September 1960 at the consumer-goods pavilion in Bucharest’s I. V. Stalin park [1]. A later model was the Enescu 2 [1].

Its designer’s memoirs say it was designed without a licence or foreign know-how, from the first fully Romanian specification; a German SABA receiver served as a reference, but it could be measured and not opened [2]. The specification gave long, medium, three short-wave bands and FM, bass and treble controls and a rated output of 3 W, with about eight tubes [2]. The prototype was approved in January 1960 [2]. In the zero series of a few dozen sets faults came and went without any pattern; the FM block was put in a sealed, copper-plated metal box with good contact to the chassis, and after a visit to France the FM coils were wound on thin finned plastic formers instead of the formers used for the other bands, about three times larger in diameter, which made production much more even [2]. The aligners also had to learn that the FM part was adjusted for a minimum, not a maximum as on AM [2]. The zero series was approved in August 1960 and series production began in October 1960; thousands were made, and FM production became routine about two years later [2].

In the source table, sensitivity is given on medium waves for 0.5 W output, selectivity for a signal ±9 kHz (AM) or ±300 kHz (FM) away, the audio frequency response at 1 MHz within 6 dB, and output power at no more than 10% distortion; the quality classes are only indicative, based on IEC recommendations and the Soviet GOST 5651/1951, as Romania had no such standard at the time [1].