THE MASS-PRODUCED ARZ-49 RECEIVER

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600310055-6
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: August 12, 2011
• Sequence Number: 55
• Publication Date: May 10, 1950
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/08/17: CIA-RDP80-00809A000600310055-6
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CENTRAL INTELLIGENCE AGENCY REPORT
INFORMATION FROM
FOREIGN DOCUMENTS OR RAL D BROADCASTS CD NO.
CLASSIFICATION CONFIDENTIAL CONFIDENTIAL Q:
Scientific - Radio
Monthly periodical
Moscow
May 1949
THIS OCCUR [NT CONTAINS INFORMATION AFFECTING M[ HAT,ONAL DEFENSE
Of THE UNITED STATES WITHIN THE MEANING OE ESPIONAGE ACT 50
N. S C SI AND S2. AS SMENOEO ITS TRANSMISSION ON THE REVELATION
OF ITS CONTENTS IN ANY MANNER TO AN UNAUTHORIZED P[RSIN IS PRO
MISIT[D ST LAW REPRODUCTION OF THIS FORM IS PROHIBITED
DATE OF
INFORMATION 1949
DATE DIST. /0 May 1950
NO. OF PAGES 3
SUPPLEMENT TO
REPORT NO.
THIS IS UNEVALUATED INFORMATION
THE MASS-PRODUCED ARZ-4 RECEIVER
During the postwar period, industry has developed and put on the market
some 20 different models of radio receivers. But, with few exceptions, they
were all second-class receivers. Only the Rekord belonged to the third class.
It is utterly impossible to consider this the proper ratio for the various
kinds of receivers on the market. The greatest demand among the people is for
cheap receivers which enable one to hear central broadcasting programs in all of
European USSR. Ana it is precisely in this category that the consumer should
have a wide latitude of choice. Yet the factories are putting out only one type
of third-class receiver and none in the class of very low-cost mass-produced re-
ceivers.
Toward the end of last year, plant laboratories were charged with the task
of correcting this deficiency and developing some mass-produced radio receivers
of the simplest type. The first receiver finished was the ARZ-49, designee. in
one of he radio plants of the Ministry of the Communications Equipment Industry
by a group of designers -- P. 1. Kruchinin, S. V. Lykov, and V. M. Sobolev.
The ARZ-49 is a two-band superheterodyne receiver operating on a 110-220
volt AC line. The long-wave band is designed to receive radio waves from 730-2,000
meters long (410-150 kilocycles); the medium-wave band, 188-.520 meters (1,600-520
kilocycles).
From the technical viewpoint, the ARZ-49 operates in the same manner as the
r..ekord, although it has c.ly three tubes. The operating characteristics should
also be better for this receiver than for the Rekord inasmuch as in the ARZ-49
there is no series connection of the tube filaments, and the tube rectifier, which
often gets out of order, was replaced by a selenium pile. It is also preferable
to the Rekord because of its power consumption -- not more than 40 watts on either
120 or 220 volts
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CORE nr71TIAL
C aroni 1. Dl: ;ijgn
`.Cite first tube (T)rpe 6A10) is a converter. The second (Type 6B8), a duo
diode-pentode, is used in r reflex circuit. It serves as an IF amplifier, a
diode detector, and the first audio amplifier. The third tube (Type 30P1M) is
the final audio amplifier.
An LC series filter, core-tuned to the IF frequency, is provided at the
input of the receiver. The schematic diagram of the input section is exactly the
same as that of the Rekord.
The D' voltage from the first-band filter is applied to the control grid
of the 6B:f tube. The amplified IF voltage is then applied to the diode of this
tube ar-1 the resulting audio signal appears across a load potentiometer which
serves as a vo]umc control. The voltage on the contact arm passes through a
bioc1dng condenser and the secondary of the first IF to the control grid of the
6B8 tube where it is amplified.
The "Arch" (automatic sensitivity control) voltage is taken from the load
circuit of the 6B8 tube and is applied through a decoupling c'.rcuit to the con-
trol. grido of the first two tubes (6A10, 6B8). It is applied to the grid of the
first tube through the grid leak, and to the second grid through an RC decoupling
circuit.
The audio load resistor in series with the plate of the 6B8 and the primary
of the second IF is coupled to the grid of the 30P1M audio amplifier through a
condenser. This completes the reflex cascade of the ARZ-49
The power-supply circuit and the manner in which the second tube is utilized
are new for commercial receivers. The tube-plate supply and the screen-grid sup-
ply is furnished by a selenium rectifier. A selenium pile of the VS-35-13a type,
consisting of 16 cells connected in series, functions as the rectifying device.
The rectifier filter circuit is the some as that in the Rekord-47. The plate
circuit of the output tube is supplied directly from the first filter condenser,
while all other high-voltage circuits are supplied through a smoothing resistor
and part of the primary winding of the output transformer. This part of the
winding serves to filter out the AC hum. The operating principle of this type
of filter was analyzed in Yu. Zinov'yev's article in Radio No 1, 1949.
For filament supply, an autot:ansforaer is provided witn two filament taps;
6.3 volts for dial illumination and the filaments of the first two tubes, and
30 volts for the filament of the last tube.
The receiver can be connected to either voltage through two protective de-
vices. When the line voltage is 127 volts, the rectifier (the selenium pile)
is connected directly to the line. When the line voltage is 220 volts, the en-
tire autotransformer winding is switched across the line acting as a step-down
transformer -- the rectifier receives 127 volts as in the previous case. inr
receiver has no special switch for 110 volts but will operate satisfactorily
in the 127-volt position of the switch.
General Description of Receiver
The nominal power output of the receiver amounts to 0.6 watts when the co-
efficient of nonlinear distortion does not exceed 7 percent.
The sensitivity at 30 percnnt modulation and 0.06 watts power output is
not less than 300 microvolts.
The selectivity is characterized by a falling off of ncL less than 20
decibels for 10-kilocycles detuning.
,ONFIDENTIAL
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I
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1OMFIDENTIAl
The reduLtlou, in the iciaU irar;:u l at the higher frequencies of both bands,
as well as of a signal with a frequency equal to the intermediate frequency, is
not less than ?0 decibels.
The frequency par,-band for all parts of the receiver including the loud-
speaker (measured by sound pressure) has a range of 200 to 3,000 cycles per
second for a discontinuity of plus or minus 10 decibels.
The automatic sensitivity control guarantees constancy of output voltage
within the limits of plus or minus 10 decibels, during variations in. input
voltage of 5,000 to 100,000 microvolts. The sensitivity of the adapter inlet
with nominal output voltage is 0,25 volts,
The intermediate frequency is 110 kilocycles. The performance of the re-
ceiver is stubl.e during variations in line voltage of plus or minus 15 percent.
Construction
The receiver f; mounted on a metal chassis. Practically all the large parts
are located on the horizontal upper part of the chassis, the small parts and con-
necting wires on the lower side.
The control knobs are located on the front panel. The knob on the left
functions as a switch and volume control, the center knob as the tuning control
and the right knob as the band switch. The Jack for the antenna and. adapter is
at the back. The receiver must not be grounded.
Many parts are the same as those of the Rekord-47. The dial is?c.rcular
with a pointer attached at the center. A Type 1-GDM-1.5 dynamic loudspeaker is
used.
This is the first cheap, mass-produced broadcast receiver. The designers
have taken great pains to make it as efficient as possible. There is, of course,
no objection to employing a reflex circuit in this type of receiver with few
tubes. The general performance of the set is all the more satisfactory because
its actual specifications are somewhat better than those originally established
which cdrried only a minimum guarantee under commercial conditions. The receiver
ins fairly sensitive, but, under city conditions, it cannot be expected to receive
a great number of stations. The main reason for buying such receivers is to re-
ceive broadcasts from local stations and from powerful broadcasting stations in
European USSR.
(Original document, available in CIA, shows external view of set, front and
rear views of chassis, and a circuit diagram
'RONFIOE mm'.
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