Tube network radio receiver "SI-235".
Tube radios.DomesticFrom 1935 to 1939, the network tube radio receiver "SI-235" was produced by the Moscow plant named after Ordzhonikidze, and from 1936 to 1941 by the Voronezh plant "Electrosignal". "SI-235" (Network Individual 2-circuit, 3-tube, model 1935) is a new massive network cheap receiver for a city radio listener and is assembled according to the 1-V-1 regenerator circuit with parallel power supply and differs little from the circuit of the BI-234 receiver ... The new radio is housed in a box with a dynamic loudspeaker, with sockets for a turntable and tuning dial lighting. The era of direct amplification receivers ended with the SI-235 receiver. "BI-234" and "SI-235" were the first receivers, the production of which was put on the conveyor. The release of these mass receivers began a new stage in the radio industry: the development of flow methods for the production of radio equipment and a new, more modern technology. Due to its simplicity and low cost, the receiver quickly gained popularity among the population. The receiver is built on 4 lamps; SO-148, SO-124, SO-122, VO-230 or VO-202 and adjustable feedback. UHF on the SO-148 lamp has a capacitive connection with the antenna, the SO-124 lamp is a detector. ULF is made on the SO-122 pentode. The anode and screen circuits of the receiver lamps are powered from a half-wave rectifier on the VO-230 kenotron. Frequency tuning capacitor - two-section, with cellulose dielectric. The receiver is designed to receive radio stations operating in the ranges DV - 714 ... 2000 meters and CB - 200 ... 545 meters. The rated output power of the amplifier is 0.6 W. Power consumption from the network 110, 127 or 220 V - 40 W. The dimensions of the model are 340x420x215mm. The receiver is assembled in a plywood case with a textured surface finish for shagreen. Removing the back panel disconnects the mains voltage. The lamps are separated by two shielded compartments, in the left one there are LF SO-124 and SO-122 lamps, in the right RF SO-148. Kenotron - VO-230 is located on a power transformer. The mains voltage is switched by jumpers. The chassis has adapter sockets (since 1938) as well as antenna and ground sockets. The controls are located in front. In the center is the tuning knob. The lower left handle is a volume control combined with a switch. Right stick - feedback. Between them is the lever of the range switch `` Kor and Dl '' (SV and DV). An illuminated vertical rotating scale is visible in a 25x30 mm window. Near the scale there is a lever for adjusting the RF amplifier. Here, below the scale, at the bottom there is an emblem with the inscription: `` Main Directorate of the Low-Current Industry ''. A bias loudspeaker with an output transformer. The price of the receiver is 250 rubles (1935). For example, the metro fare in those years was 30 kopecks. During the Second World War, all the receivers in the possession of the population were deposited by the state, in some photographs there is information of this time.
