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               History: 
                Radio RBM, firstly named as RB (Radio, Base), was designed before 
                the WW-II, in the 1938, in the Research Center of Communication 
                of Red Army, by a special research group guided by colonel Sosunov. 
                Special variant of RB named as RB-40, that had low weight because 
                it was made in an aluminum cabinet was produced from end of 1939 
                for spy and partisan. It was made near 1000 RB-40, but then its 
                producing was stopped because the aviation need aluminum. In the 
                1942 some modifications were done in the radio, and RB was named 
                as RBM (Radio, Base, Modified). In the 1943 both with RBM was 
                produced RBM-5 that has 5 watts power compare to 1 watt that RBM 
                has. After WW-II other modification of RBM named as RBM- 1 was 
                produced. RBM-1 was produced until end of 50s. Some samples of 
                RBM-1 was produced for export (see picture with 
                Latin letters on the front panel). 
                
              Composition: 
                RBM- 1 consists of from two boxes, one is the transceiver 
                other is its supply unit. 
                
              Transceiver 
                has dimension of 345x195x260-mm, weight of 13 KG. It works at 
                two frequency ranges, I-5.0- 2.75 MHz, II - 2.75-1.5 MHZ, has 
                CW and AM modes. Transmitter made on vacuum tubes.  
                
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               WW- 
                II. USSR, Leningrad Front, 1943. 
              Radio 
                RB 
                 
                
                
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               Transmitter 
                has 1 watt output(in reality 1.5 watts), plate current 35-mA and 
                heater current 1-A.  
                
              Receiver 
                has sensitivity of 10-μV at AM and 3-μV at CW, plate 
                current 10-mA and heater current 0.5-A.  
              Transmitter 
                and receiver use common units as: an antenna and output audio 
                transformer, that does modulation for transmitter at AM mode and 
                audio at receiving mode.  
                
              Power 
                supply has three batteries of BAS-80 for plate and 
                a NiCad accumulator 2NCN-24 for heater, weight of 14 KG. The Power 
                Supply run the radio during 24- 36 hours. 
                
              Purpose 
                of RBM is to do reliable simplex communication at any conditions. 
                Distance of the communication depends on antennas that use with 
                the radio.  
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              Export 
                Sample of RBM-1 
                 
                
                
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