Zefir S 631 TN2
Electronica · 1969
- Manufacturer
- Electronica
- Country
- Romania
- Year
- 1969
- Decade
- 1960s
- Category
- Radio
- Type
- Radio receivers
- Documentation score
- 2/5
- Last edited
- 03 OCT 2026
Specifications
- Transistors
- 7 transistors and 2 diodes (II.3 annex: SA102 (EFT319), SA102 (EFT319), SA101 (EFT319), SB171 (EFT352/353), 2 × SB176 (EFT323))
- Wavebands
- LW 140–310 kHz, MW 540–1630 kHz
- Sensitivity
- 300 µV/m (ferrite antenna)
- Selectivity
- 16 dB
- Output power
- 0.1 W
- Loudspeakers
- circular, 7 Ω, 0.3 VA (Gold Star: 7 Ω, 0.5 VA)
- Inputs / outputs
- earphone jack, external antenna terminal
- Construction
- miniature parts on a single printed-circuit board
- Power supply
- 6 V (4 × 1.5 V cells)
- Power consumption
- 12 mA without signal, 65 mA at nominal output
- Dimensions
- 142 × 88 × 40 mm (plastic case, in a leather case with an accessory compartment)
- Weight
- 454 g without batteries, 520 g with batteries
Description
The Zefir S 631 TN2 is a pocket transistor radio for long and medium waves, made by Electronica in Bucharest [1][2]. Production started in 1969, with parts almost entirely made in Romania; the book’s photograph caption calls it the first pocket radio [1]. Its export version, from 1970, was the Gold Star [1].
Section II.3 lists it with the Electronica S 631 T among the small portables of 1960–1965, with 700 µV/m sensitivity and 14 dB selectivity [2]; it also calls the Electronica S 632 T the first pocket radio [2].
Tehnoton in Iași made a radio named Zefir in 1975, 1977 and 1979 [3].
In the source table, sensitivity is given on medium waves for 50 mW output and a 20 dB signal-to-noise ratio, selectivity for a signal ±9 kHz (AM) or ±300 kHz (FM) away, and output power at no more than 10% distortion [1].
Gallery
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Schematics
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Documents
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References
- [1]D. F. Lăzăroiu, N. Millea et al. – „Electronica românească. O istorie trăită”, vol. I, AGIR, section II.4 „Uzinele Electronica, 1966–1981”, pp. 160–161 and annex II.4.2 „Radioreceptoare cu tranzistoare”, pp. 184–188
- [2]D. F. Lăzăroiu, N. Millea et al. – „Electronica românească. O istorie trăită”, vol. I, AGIR, section II.3 „Uzinele Electronica, 1960–1965”, annex II.3.2, pp. 149–151
- [3]D. F. Lăzăroiu, N. Millea et al. – „Electronica românească. O istorie trăită”, vol. I, AGIR, section III.1 „Întreprinderea Tehnoton – Iași”, pp. 305–306, annex III.1.1 „Radioreceptoare produse de Tehnoton”, pp. 308–311