July 28, 1924 can be considered as the starting point
of production of home receiving devices in the USSR. On
that day The Soviet of People's Commissars (The
Government) of the USSR passed a decree "On private
receiving radio stations", which gave the citizens
the right to own a radio set. And already in autumn of
1924 the Trust of Low Voltage Factories in
Moscow put out the first industrial home radio receiver -
"LDV" (Home Detector
Broadcasting"). It had a fixed tuning to the wave of
the Comintern Radiostation (3200 m). But it did not mean
that tuning was no problem. The
radio was based on a crystal detector with "an
active point". The edge of a steel wire was touching
a polycrystal of natural semiconductor. With a small knob
the
position of
the steel pin could be changed. After some attempts one
could "feel" the detecting p-n-transition on
the border of the "pin-crystal" and the
broadcast was heard in the headphones. No one could move
about the room not to "shake off" the active
point.The author
has a similar detector at his disposal and tests showed
that the ratio of direct and opposite resistance at the
active point could reach 1:20. Of course, it is much
lower than with a modern diode , but then it was
sufficient for detection of signals of powerful local
R-stations.
The modifications of radio "LDV" are known
as "LDV-2" and "LDV-4".
Then followed "LDV-3", "LDV-5"
and "LDV-7" - complicated
devices with changeable inductivity of the coil in
200-1500 m band. The detector receiver "Proletary"
was also very popular.
The first in USSR valve radio was produced at the end
of 1924 by the above-mentioned Trust of Low-Voltage
Factories. It was the receiving set
"Radiolina", consisting of several blocks. The
first of them contained a tunable coil with
a span of 450-3400 m. The blocks of detector and RF-Audio
amplifiers were connected to it.
 |
"Radiolina" |
They were assembled in a separate case by 2,3 and 4
pieces. The anodes of the receiver's tubes were
battery-sourced. In the first lots of the
"Radiolina" the tubes R-5 with tungsten cathode
were installed using the current of about
0,6 A. That is why accumulating battery was needed to
feed the heater. The necessity of frequent recharging the
battery strongly restricted the use of the radio set even
in towns and cities. When new tubes of the
"micro"-type appeared which used 10 times less
energy there was a possibility to change the accumulators
for galvanic elements. The "Radiolina" set had
only one resonance coil and a very low sensitivity and
selectivity. An electromagnetic horn speaker
"DP" or (later) a diffusion-type
"Rekord-2" was included into the set.
Almost simultaneously with the "Radiolina" a
cheaper single-tube regenerative receiver "R-1"
was produced in which headphones were used.
The next series of Soviet radio receivers became
really "mass media". It was a line of type
"B" sets designed by E.Borusewich (an engineer
of the Trust of Low-Voltage Factories). The production of
those sets opened in 1926 with models "BV"
(one-tube), "BT" (three-tube)
and "B4" (four-tube). The
"BT" and "B4" had equivalent schemes
- two tunable coils and the structure 1-V-1 and 1-V-2
respectively. The "BV"-receiver could work with
a usual crystal detector without any batteries. In all
the stages of these radios
3-electrode tubes of the single type were used. The
R-sets worked within 250-2000 m bands and enabled to
receive broadcasts on the electromagnetic speaker
"Rekord". In 1928 an improved version of the
"B4"-set appeared, which was named "B4N". It was also tuned out by the
"Moselectric Works" (in Moscow).
A more powerful tube of UO-3 type was used in audio
output. The model "B4Z"
("B4"-closed) became a further modification of
the "B4N" set. The scheme being unchanged all
the tubes were put inside a case.
Together with the "B4N"-set a universal
2-tube receiver 0-V-2 of "PL-2"-
type was produced. It could operate as both one- or
two-tubed. Besides, in its construction usual
"micro"-tubes and two-grid tubes of MDS-2 type
could be used, the latter working on low anode voltage.
In all the above-mentioned receivers tubes of direct
heating were installed. The output of radio model "DLS-2"
was the first attempt to make net-supplied receivers. It
is a device with a crystal detector combined with a
2-tube audio amp and a vacuum rectifier. It works using
UO-3 tubes of direct heating. The output of tubes with
indirect heating was the beginning of a
new era in development of radiotechnics because then the
problem of complete sourcing of radios from AC net was
solved.
Among the first receivers of this type one can mention
radio "E4S-2" of Orjonikidze
Works ("Screened 4-tube
AC-sourced") constructed by E.N.Genishta and radio "EKL-4"
of Kozitsky Works (Leningrad). In both new
tetrode tubes were applied. The further
improvement of the former became radios "E4S-3"
and "E4S-4" and of the latter - radio of "EKL-34"
type. All those AC receivers were assembled according to
the structure of direct amplification 1-V-2 using 4-volt
glass tubes of indirect heating types
SO-124 and SO-118. A triode UO-104 of direct heating was
used in audio output. Those receivers enjoyed a wide
spread among urban listeners. Just to mention also radios
"5NR-3" and "RP-8" with the schematics similar to
the above. The "U4S-1"
set of Ukrainian make was also known.
In 1934 the Orjonikidze Works produced a
battery-supply receiver "BI-234"
("Battery Individual") which gained a wide
popularity among the rural listeners. A similar radio
named "RPK-9" was later produced by Leningrad
"Radist" Works. The difference was in their
outlook.. The peculiarity of the set was that it could work
using not a full set of tubes. Depending on their quantity the
set could be switched on in the configurations 1-V-1, 1-V-0,
0-V-1 or 0-V-0. The mode of reception was set by replacement of
the bridges. Its modifications are known to be the "RPK-10" and "RPK-11"
.
In 1935 the same Orjonikidze Works produced a new
AC-radio
"SI-235" ("AC-supply
Individual" - constructed by P.A.Lokhvitsky), wich
soon became the most numerous receiver among the urban
listeners of the USSR.
With this radio the era or direct amplification receivers
ends. They were followed by multi-band superheterodynes -
the ancestors of modern radio receiving systems.
In 1930's the output
of cheap crystal radios continued. Among them there were
the "DV"
,
"P-8"
and some
others.
