AN ALL-UNION STANDARD ON RADIO-BROADCAST RECEIVERS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000700040512-7
• Release Decision: RIPPUB
• Original Classification: R
• Document Page Count: 5
• Document Creation Date: December 22, 2016
• Document Release Date: October 28, 2011
• Sequence Number: 512
• Publication Date: February 21, 1952
• Content Type: REPORT

Declassified in Part - Sanitized Copy Approved for
STAT
CLASSIFICATION RESTRICTED RESTRICTED
SECURITY INFOAMAT70N
CENTRAL INTELLIGENCE AGENCY REFGRT
INFORMATION FROM
FOREIGN DOCUMENTS OR RADIO BROADCASTS CD NO.
HOW
PUBLISHED
Scientific - Blectronice, radio receivers,
standards
WHERE
PUBLISHED Moscow
DATE
PUBLISHED Sep 1951
LANGUAGE Russian
nu rocrnn wnuu uroauno~ unrnar na unom oanm
er ra^ rams nm~ nrau m anuar or unrawa av w
r, a. e.. a aar u.n aunu. m nuanuuoa oa m anaunoa
rr m aoanrn a an aauu m u rumoama nnoa o rao
aonao n u~. aanoaurnoa or nu roan a raoaiurro.
DATE OF
INFORMATION 1951
DATE DIST.d/ Feb 1952
N0. OF PAGES 5
SUPPLEMENT TO
REPORT N0.
THIS IS UNEVP.LUATED fNFORMAT'ON
AH ALL-UAIOP STANDARD Oft RADIO-BROADCAST RECEIVS.RS
State All-Union Standard (GOST) Ro 5651-51, "Vacuum-Tube Radio Receivers;
Classification; General Parameters," includes all types of vacuum-tube broad-
cast receivers, both line (ac and dc) and battery operated. The parameters
specified by this GOST refer to superheterodyne receivers, but Class 3 and 4
receivers, sane of which use straight amplification circuits, should have
characteristics equal to those given in the GOST.
The GOST does not apply to communications receivers, automobile radios,
and ultrashort-xave receivers.
The receivers are divided into four classes from the standpoint of their
electrical and acoustic chare,cteristice. Receivers of the highest quality are
designated Class 1 and the simplest and cheapest ones, Class 4. There will be
line and battery receivers in all classes except Class 1, the requirements of
which can be met only by line receivers. Some characteristicz of battery
receivers vary from the norms established for line receivers. Thus, for exam-
ple, the output power Por battery receivers has been set considerably below
that for line receivers, vhirh is quite natural since the output power is
related to the supply power used. On the other hand, the norms for frequency
stabilit~? for battery receivers are more rigid since the initial heating of *he
tubes and parts in these receivers has less effect on their electrical charac-
teristics than in line receivers.
Nith regard to the simplest (Class 4) receivers, this GOST is conceived
mainly with the more important electroacoustic characteristics, those which
determine the quality of the sound produced. Norms for other parameters
should be established by the specifications governing the particular receiver
types. Therefore, the omission in this GOST of certain parameters for Class 4
receivers should be understood in this xay.
mil
NSRB
- 1 -
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We shall now consider the fundamental parameters determining the classifica-
tion of a receiver.
The rated power, i.e., the output power (for a harmonic content not exceed-
in3 the value established by this COST for each class of receiver) is one of the
most meaningful parameters of receiver classification. The values established
are: at least 4 va ~oviet sets are csuelly rated in volt-amperes rather than
watt] for Class 1 line receivers, 1.5 va for Class 2 ac line receivers, 0.15 va
for Class 2 battery receivers, and 0.5 va for Class 3 line receivers.
The output power of Class 3 battery receivers and all Class 4 receivers
has not been standardized by this COST and should be governed by specifica-
tions.
Tine prescribed power supply for Class 1 line receivers is a 110-, 127-,
or 220-volt ac line. The standard supply for line receivers of the other
classes is ac with the above voltages, but universal ac-dc supply may be pro-
vided for. The power supply of battery receivers of all classes may be obtained
from primary-cell batteries or other independent current sources.
The power consumption of line receivers is not standardized and is deter-
mined by the number of tubes used.
For battery receivers, the maximum total power which may be drawn from
plate and filament batteries is: Class 2 receivers, not over 1.9 w; Clews 3
receivers, not over 1.3 w; and Class 4 receivers, not over 0.8 w.
The frequency bands for Class 1 receivers are given individually for each
receiver type in its specifications. nor Class 2 receivers, the following beads
xere established: 150-415 kc (2,000-723 m) on long waves, 520-1,600 kc
(575-187 m) on medium waves, and 3.95-12.1 Mc (75.6-24.8 m) on short waves.
Class 1 and Class 2 receivers must have aband-spread arrangement to permit
coverage of the narrow regions set aside for radio broadcasting (49, 41, 31,
and 25 m).
Class 3 and Class 4 receivers should cover the long- and medium-xave
bands, i.e., frequencies of 150-415 kc and 520-1,600 kc, respectively. Clews 3
receivers may have a short-wave band covering 3.95-12.1 Mc (75.6-24.8 m).
In Clews 4 receivers, an arrangement for reception of several pretuned
stations in the long- and medium-vave bands is authorized i~ iieu of continuous
band coverage, Por the sake of simplification.
The intermediate frequency for receivers of all classes is established at
465 f 2 kc. This will eliminate the use of different intermediate frequencies
(there are at present receivers uainq intermediate frequencies of 456, 460,
465, and 469 kc) xhich has complicated correct receiver adJustment during
repair and upset the standardization of receiver unite. The use of an inter-
mediate frequency oi' 110-115 kc is authorized only for Clews 3 and Clsae 4
receivers; this is z simple and inexpensive means of obtaining the required
sensitivity and selec`_i.vity at the expense of a slight decrease in image-
frequency attenuation.
The sensitivity, measured at a modulation factor of 0.3 and 0.1 rated out-
put power, has been standardized by the COST with a very important limitation
incorporated for the first time, namely, that the ratio of the effective signal
at the receiver c~tput side to the noise voltage (the internal noise of the
receiver and the background noise) should be at least ten to one (20 db).
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STAT
For Clara 1 :ecei-rers, the sensitivity, measured ea indicated above, moat
be et least 50 pv over the entire band and at least 200 pv for pretuned stations,
when the latter are used. For Class 2 receivers, the sensitivity moat beat
least 200 ?v oa long sad medium waves and at least 300 pv on short waves and
pretuaed stations. For Class 3 line receivers, the aenai*.ivit,~ must be at
least 300 ?v on long and medium waves and 500 ?v on short waves. For Class 3
battery receivers, the sensitivity must be at laaet 400 pv.
The sensitivity Prom the phono pickup hack for rated output power should
be at least 0.2 v for Clara 1 receivers, and at least 0.25 v for all Claos 2
receivers and Clara 3 line receivers. Class 3 and Class 4 battery receivers
.eve no provisions for pickup ,jacks, which likewise are not compulsory for
Class 4 line receivers.
The skirt selectivity, i.e., with s detuning of t 10 kc, should be at
least 46 db (200-fold attenuation) for Class 1 receivers, at least 26 db
(20-fold attenuation) for Class 2 receivers, and at least 20 db (10-fold atten-
uation) for Class 3 receivers.
In the case of receivers with variable pass bands, the selectivity is
determined for the narrow band.
The image-frequency attenuation should be at least that indicated in
Table 1.
Receiver
Claee
Tabl
Long Naves
e 1
Medium Waves Short
Naves
1
60 db
(1,000-fold)
50 db
(300-fold) 25 db (
20-fold)
2
36 db
(60-fold)
30 db
(32-fold) 12 db (
4-fold)
3
26 db
(20-fold)
20 db
(10-fold) Hot rtg
adardiaed
Frequency shift of the oscillator due to internal heating (frequency
stability), defined ae the difference between two readings of the oscillator
frequency, the first taken 5 minutes and the second 15 minutes after the
receiver is turned on, should not exceed the values shove in Table 2.
Manual volume control should effect a change in the output voltage of no
less than 50 db (300-Fold) in Class 1 receivers and 40 db (100-fold) in Clear 2
and Class 3 receivers.
The attenuation of an intermediate-frequency interference signal should
be at least 40 db (100-fold) for Class 1 receivers, 34 db (50-fold) Por Class 2
receivers, and 20 db (10-fold) fir Class 3 receivers.
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Tone control is :ompuleory only in Clnse 1 and Class 2 receivers. Class 1
receivers should have provision for separate control of the lower and higher
audio Frequencies to permit the boosting of the lower frequencies by at least
4 db (1.6-fo18) and of the higher ones by at least 6 db (2-fold), na well ns
the suppression of the lover and higher audio:prequencies by at least 6 db.
Buppression of the h ,firer audio frequencies by at least 6 db is required in
Class 2 receivers, and, in addition, 1t is recommended that provisions be
made for boosting and suppressing the lover audio-frequencies by at least 3 db
(1.41-fold).
The background noise level nt the output aide of line receivers, measured
with the volume control set at maximum amplification, should be lower than the
rated output power by no less than 46 db (200-fold) for Class 1, 37 db (70-fold)
for Class 2, and 26 db (20-fold) for Class 3 receivers.
The automatic volume control should ensure a maximius voltage change at
the receiver output of 12 db (4-fold) when the input voltage changes by 60 db
(1,000-fold) in Clasc 1 receivers a change of 8 db (2.6-fold) when the input
voltage changes by 26 db (20-fold in Clara 2 receivers, and a change of 10 db
(3.4-fold) rhea the input voltage changes by 26 db (2C-fold) in Class 3
receivers.
The frequency response for the amplifier section of the receiver (fidelity
curve), xith respect to sound pressure, should guarantee the reproduction of an
audio-frequency b;:nd having the range indicated in Table 3~
Tvne of Receiver
Receiver Class
Table Model
Console
cps
cps
1
60 - 6,5oe
50
- 6,500
2
loo - 4,000
80
- 4,000
3
150 - 3,500
--
4
200 - 3,000
--
The frequency bands listed in Table 3 should be reproduced xith variation
sot exceedinv 14 db (5-fold.) on sll bands, except fox' irequencies under 250 cps,
where a variation of 18 db (8-fold) is permissible.
The average sound pressure developed by receiver loud-speakers at rated
o~itput power on the Frequency bands etipulatra above and measured at a distance
of one meter from the receiver (for battery receivers it is further specified
that they must not nse more power than the norm prescribes) should be at least
20 bars for Class 1 sets, i0 bare for Class 2 line receivers, 3 bars for Class 2
end Class 3 battery receivers, 4.5 bars for Class 3 line receivers, end 3.5 bare
for Class 4 line receivers. For Class 4 battery receivers under the same con-
dition, a sound pressure norm of 2.5 bars has been established, which, however,
can drop to 1.5 bars if the power urawn is reduced correspondingly.
The harmonic content is standardized for the entire amplifying section of
the receiver and is measured by sound pressure at rated output power. This COST
establishes permissible harmonic contents at various frequencies, as shown is
Table 4, in contrast to former systems which evaluated nonlinear distortion
only at one frequency, namely, 400 cps.
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Harmonic contents of up to 15$ are permissible for the loxest audio fre-
quencies of the response band ~:stabliahed for Class 1 and 2 receivers.
All line receivers are required to have a pilot light to indicate thst
the receiver ie turned one xhile battery receivers must have a mechanics: evice
for this purpose. The GOST authorizes electrical indicators for battery
receivers (for examples a neon lamp) but does not make them conpulsory. Tun-
ing indicators are also required in all Class 1 sad 2 line receivers.
A variable pass band ie compulsory only in Class 1 receivers; it is
not required in Clare 2 receivers. A provision fur connecting an external
loud-speaker to the receiver la required only in Class 1 and Clare 2 receivers,
xhile s provision for connecting the receiver loud-speaker to the aired radio
netvork is obligatory for all battery receivers. ~Tnis requirement ie not com-
pulsory for line receivers. The recommended number of vacuum tubes Se not sore
than seven for Class 2 receivers, five for Class 3 receivers, and four for.
Clare k reoei~ere. The Gost does not regulate the number of tubes for Class 1
receivers.
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