As a matter of fact, mankind owes the appearance of compact tape recorders to reporters. Therefore, the first portable devices were called reportage. And, unlike their “big” brothers, they had an extremely interesting design of the tape drive mechanism.
The problem of creating a compact portable mechanism for recording lay in the impossibility of technologically manufacturing a sufficiently compact electric motor with the required parameters. Therefore, as a "substitute", a spring-loaded mechanism, which had been used before in gramophones, was introduced. Of course, even such a solution, plus lamps and a battery, made these devices portable and compact rather approximately.
Nagra I.
Nevertheless, after the Second World War, such reporting devices began to win their place. But if we talk about "normal" acceptable dimensions, the first portable tape recorder was the Nagra I, created in Switzerland in 1952. And the first serial devices were Nagra II and the Soviet MIZ-8, the beginning of production in 1953.
The first domestic * reporter * MIZ-8.
The dimensions were 30x15x11 cm for the Swiss apparatus, and 27x17x15 cm for the MIZ. The devices weighed 4.5 and 6 kg, respectively, without batteries. The Nagra had a belt speed of 19.5 cm / s, and the Soviet apparatus was 9 cm / s. Because of this, in terms of amplitude-frequency characteristics, our mechanism was inferior to the imported one. At a speed of 19 cm / s, the spring mechanism worked for about 4-5 minutes. It was possible to "recharge" the spring when the mechanism was running.
Dnipro-8.
MIZ-8 was continued in the form of a tape recorder "Dnepr-8", produced by the Petrovsky plant in Gorky and the Kiev Radio Equipment Plant since 1954. The film speed was slightly increased, up to 96 mm / s. The duration of a single track recording was 15 minutes, and every five minutes it was necessary to tighten the spring of the K2 type mechanism. A minute scale from 5 to 1 was used to indicate the remaining run time.
Promotional video:
Spring mechanism type K-2, * Dnepr-8 *.
The electronic components were powered by three batteries - two 1KS-U-3 (1.6 V), with a capacity of 3 Ah. and one GB-60 (67 V), capacity 0.1 A.h. This kit provided 20-25 hours of operation. The tape recorder was placed in a leatherette suitcase. An elegant and wonderful device.
One of the factors that * interfered * with the operation of the tape recorder is the high detonation coefficient inherent in spring mechanisms. The American Amplicorp Magnemite 610 tried to overcome it by installing a massive disc.
But the compact tape recorders with electric drives that appeared in the late 50s turned out to be more convenient, reliable and progressive. The first was Stellavox SM-4, released in 1957, Reporter -2 (and model 3), Nagra III … The time of springs has passed, the era of compact electric motors has arrived.