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.
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
II. USSR, Leningrad Front, 1943.
has 1 watt output(in reality 1.5 watts), plate current 35-mA and
heater current 1-A.
has sensitivity of 10-μV at AM and 3-μV at CW, plate
current 10-mA and heater current 0.5-A.
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.
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.
of RBM is to do reliable simplex communication at any conditions.
Distance of the communication depends on antennas that use with
Sample of RBM-1