Diana HM 1 E 59-740

The Diana HM 1 E 59-740 is a hybrid (tube and transistor) black-and-white television set of the hybrid 1 family, made by Electronica in Bucharest on the chassis of the Saturn, with a 59 cm, 110° picture tube [1]. The hybrid 1 family differs from the Saturn by its channel selector, with mechanical band switching, varicap tuning, fine-tuning memory and silicon transistors, and by changes to the AGC, which led to a different main circuit board; it was rated quality class II [1].

In 1971–1972, as Romanian transistor production grew, Electronica replaced tubes with transistors in the low-power stages – channel selector, video-sound and sound IF amplifiers, video amplifier, AGC and sync separator – creating a new generation of “hybrid” sets with longer life, lower power consumption and fewer imported tubes [1]. The first was the Saturn E 59-710 of 1971 (hybrid 1, H1), which kept six proven tubes for the audio, vertical and horizontal power stages and used 14 transistors, only three of them imported, in the small-signal stages [1]. HS stands for a hybrid set with a silicon-transistor channel selector, three times cheaper to make than the tube turret tuner [1]. In 1971–1976 about 2.4 million hybrid H1 and H2 sets were made (up to 500,000–550,000 a year) for the home market and for export [1].

Other models of the same group: Venus I, Venus HS E 47-740, Modern HS E 47-741, Electra E 59-721, Opera HS E 59-741, Diana E 59-720, Diana 2 E 61-740, Astronaut E 65-720.

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].