Portable radio `` Selga-403 ''.
Portable radio receivers and radios on p / p.DomesticThe radio receiver "Selga-403" in 1971 was experimentally produced by the Riga plant named after A.S. Popov. The radio receiver is designed to receive radio stations in the DV and MW bands. Reception is carried out on an internal magnetic antenna, but it is possible to connect an external antenna. Headphones can be connected to the receiver. The receiver is made according to a superheterodyne circuit with three transistors and one integrated circuit "Ritm-2" / 2KZhA-421 / (some of the copies had a microcircuit "Ritm-1"). The circuit of the input circuit and the converter is similar to the circuit of the Selga-402 model, with the difference that an RC filter is included in the circuit of the communication coil of the DV range in order to improve selectivity. The IF path, the detector and the pre-amplification stages are made on an integrated circuit containing 6 transistors, 22 resistors and 7 capacitors. The output stage of the LF amplifier is made on KT315A transistors according to a push-pull transformer circuit. In comparison with other receivers, the printed circuit board is reduced here due to the use of a microcircuit with dimensions of 26x22x13 mm. The use of the 0.5GD-21 loudspeaker improved the acoustic parameters and increased the output power to 220 mW. Powered by 6 elements 316. The dimensions of the radio receiver are 195 x 95 x 50 mm. Weight 650 g. In total, 273 Selga-403 radios were produced, after which it was removed from the assembly line, and the production of Selga-402 radios was continued.
