SOVIET VEF M-697 AND BALTIKA RADIO RECEIVERS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600350246-0
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: August 23, 2011
• Sequence Number: 246
• Publication Date: October 11, 1950
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/09/14 :CIA-RDP80-00809A000600350246-0
SOVIEP VEF M-69'7' A1~ BALTTKA RADIO RECEIVERS
In 1949, the VEF Plant (State Electrotechnical Plant, Riga), besides menu=
facturing the VEF M-557 receiver which is popular with radio amateurs, put out
a somewhat improved model under the trade name VEF M-697. Ia 1950, the plant
started producing the Ba1t:+Y.a second-class receiver. Both of these receivers
are described below.
VEF M-697 Receiver
The M-697 receiver is a table model (568 x 251 x 367 mm) witb a high-
seasitivity electrodynamic speaker developed by VEF. In addition to a per-
manent magnet, the speaker has & magnetizing coil which also fl~nctions as a
filter choke.
The M-697 has the following wave bands: long-wave, 2,000-732 m (150-
410 kc); medium-wave, 577-200 m (520-1,500 kc); short-wave, 70-24.8 m (4,280-
12,100 kc). The intermediate frequency is 469 kc.
The if pass band of the receiver is not adjustable. Instead, a step
tone control for loe frequencies is included in the negative feedback circuit.
The output stage uses a 6V6 tube with negative feedback which consider-
ably reduces the nonlinear distortion. Anew method oY connecting the pri-
mary winding for various line voltages permits a reduction in copper losses.
Baltika Receiver
The Baltika is also a table model (500 x 280 x 36o-mm) with two double
control knobs. ~
Sanitized Copy Approved for Release 2011/09/14 :CIA-RDP80-00809A000600350246-0
~ y ~ CONFIDE~~l~~
? CLASSIFICATION Co1~FIDENi'IAIA
t i;+Ell64t~ SO
,,;,~"~'?."?' -- INFORMATION 1950
CENTRAL INTELLIGENCE AGENCY kEPORI~
1N FORMATION FROM
FOREIGN DOCUMENTS OR RADIO BROADCASTS CD N0.
SUBJECT Scientific - Radio, receivers
HOW
PUBLISHED Monthly periodical
WHERE
PUBLISHED Moscow
DATE
PUBLISHED May 1950
LANGUAGE Russian
THIS DOCV YLNT CONTAINS IN/ORY ATION AIf LCTINO 7N[ NATIONAL DL/[N!l
Ol iN[ UNITLD STAT[S YIITNIN TN[ Y[A NINO 0/ [3110 NAG[ ACT [0
U. 9. C.. 31 ANO If, AS AY[MDLD. ITS TRANSMISSION OR 7NC RLV[LATIOX
01 ITS CONTLNTS IN AMY YANN[R TO AN UNAVTN ORI[[D PLRSON 1! PRO?
NI81T[D ST LAM. R[IRODUCTIOX OL TN19 TORY IS PRO HI LIT[D.-
DATE DIST. ~~ Oct 1950
SUPPLEMENT TO
REPORT N0.
50URCE Radio, No 5, 1950. pp 51-57?
 Sanitized Copy Approved for Release 2011/09/14 :CIA-RDP80-00809A000600350246-0
_~
'The Baltika operates on four wave bands as follows: long-wave 2,000 -
732 m (150-410 kc); medium-wave, 577-387.3 m (520-1,600 kc); first short-
wave band, 24.8-33.3, (12,100-9,000 kc); second short-wave band, 32.7-76.0
m (9,200-3,950 kc). The intermediate frequency is 465 kc.
The first tube of the receiver (6SA7) is s frequency converter; the
second (6SK7) is an if amplifier; the third (6SQ7) is the AVO detector,
snd first audio amplifier; the fourth (6V6) is a power ampllfier;,Lhe fifth
(5~s4S), a rectifier, sad the sixth (6E5), a visual tuning indicator.
The electrical specifications are alike for both receivers, except
f`or oscillator frequency stability, which is somewhat higher in the Baltika
than in the M-6g7. The rated output power, when the harmonic factor equals
796, is not less than 2. Sensitivity for "long and medium waves is not leas
than 200 mv; for short waves, 300 mv. Signal attenuation for 10 kc detuning
on medium and long waves is not less than 26 db. Attenuation of image chan-
nel at higher frequencies of the medium- and long-wave bands is not less than
30 db; in the short-wave band, not less than 12 db. '
The frequency characteristic, taken according to sound pressure, is
within 20 db in the 100-4,000 kc frequency band, with the harmonic factor,
also measured by sound pressure, not exceeding 10 percent. The AVC provides
for a variation of output power not greater than 8 db when the signal volt-
age at the input changes 20 times.
Drift of the oscillator frequency in 10 minutes after 5 minutes warm-up
is as follows: in~the Baltika receiver for long and medium waves, not over
one kc, for the second short-wave band, not over 4 kc, sad for the flret band,
not over 6 kc; in the M-697 receiver for long and medium waves, not over 1.5
kc, and for short waves, not more than 6 kc. Sensitivity at the sound pickup
input corresponding to rated power, at a requency of 400 cps,emounta to 0.25
volt. The level of background and inherent noise at the output as compared
with rated power is minus 30 db. Power required from the line, 68 watts.
The basic structural details differentiating the L..ltika from the M-557
include the following:
Anew, simplified design of the two-gang variable condenser ensuring
the necessary overlapping of the bands,~highly stable capacitance, small
losses, and a more desirable variation in capacitance. Moreover, the bet-
ter arrangement and mounting of the unit on the chassis eliminates the pos-
sibility of microphonic effects in the receiver -- which caused so many com-
plaints from owners of the M-557?
Reducing the dimensions of the hf and if coils made it possible to use
one-third the amount of carbonyl iron, wire, and pressed power material in
the cores,
Tempeaature?compensation by means of a ceramic condenser considerably
increases the frequency stability of the oscillator itt the Baltika.
However, despite these special features which make the Baltika more
desirable than the previous models, some structural defects should be noted.
First of ell., the dial indicator is not illuminated, which makes, tuning dif-
ficult. The absence of a ,jack x'or an additional loud-speaker is also a draw-
back, since such ,jacks make a wider use of the receiver possible.
Sanitized Copy Approved for Release 2011/09/14 :CIA-RDP80-00809A000600350246-0
 50X1-HUM
Sanitized Copy Approved for Release 2011/09/14 :CIA-RDP80-00809A000600350246-0
Sanitized Copy Approved for Release 2011/09/14 :CIA-RDP80-00809A000600350246-0