Portable transistor radio "Progress".
Portable radio receivers and radios on p / p.DomesticSince the beginning of 1957, the Progress portable transistor radio receiver has been experimentally producing the Voronezh Radio Plant. "Progress" is the third Russian experimental portable transistor radio receiver. It is made on the basis of the Surprise radio receiver and in its case. The radio is built according to a superheterodyne circuit with seven transistors of the P402, P13A types. It is designed to receive radio stations in the range of DV, SV. The radio is received via an internal magnetic antenna. The dimensions of the receiver are 220x157x70 mm. Its weight with batteries is 1.3 kg. Sensitivity 2 mV / m in the LW range and 1 mV / m in the MW range. Selectivity on the receiving channels 20 dB. The nominal output power of the amplifier on a loudspeaker type 0.5GD-10 is about 200 mW. The range of effectively reproducible sound frequencies, not more than 150 ... 4000 Hz. IF = 465 KHz. Power is supplied from two KBS-L-0.5 batteries connected in series. Duration of continuous operation from a fresh set of batteries is about 60 hours. The body of the radio receiver is made of special laminated wood and covered with colored plastic. The assembly is manual, a total of 300 receivers were assembled. In 1958, at the World Exhibition in Brussels, the radio was awarded a gold medal.