An important part of the Cold
War was fought over radio waves and this battle
continues to this day. All kinds of radio
signals, from communication signals in voice,
Morse or data, to technical signals such as
radar, navigation, telemetry and radio jamming
are transmitted and intercepted, but it was also
a war of words between many shortwave propaganda
stations. There are many audio samples at the end
of this page that show how the Cold War actually
sounded.
Especially during the Cold War,
the arms race and the need for intelligence
fueled a rapid development of sophisticated
electronics. The interception and analysis of
enemy signals became just as important as the
performance and protection of one's own signals.
Signals intelligence (SIGINT), the gathering of
intelligence by interception of signals,
comprises two main parts: communications
intelligence (COMINT) and electronic intelligence
(ELINT).
COMINT focuses on voice, Morse
and data communications to retrieve the content
of the messages, the identity and location of the
person, organisation or unit that broadcast, and
the broadcast frequencies and schedules. These
communications are often encrypted to protect
them from eavesdropping, requiring cryptanalysis
to make them readable. Even when all
cryptanalytic attacks fail, information can still
be extracted by traffic analysis, the deduction
of information from patterns in the
communications (message size and volume, time,
location).
ELINT comprises the
interception and analysis of signals from weapons
systems, navigation, guidance and radar systems,
to find out which systems the opponent uses, how
the equipment works and how it performs. Goal is
to know the opponent's capabilities, his order of
battle, and to develop electronic counter
measures (ECM) against his equipment. The
opponent, on the other hand, will develop
electronic counter-counter measures (ECCM), for
instance encryption or frequency hopping, to
prevent exploitation or jamming of his systems.
ELINT comprises the TechELINT collection of
technical signals and OpELINT to gather
operational intelligence.
SIGINT truck near
Czechoslovakian border mid 1960's
Source: ASA Det J Schneeberg veterans
East versus
West
In todays world of global
communications, the Internet and freedom of
travel, we tend to forget that, only a few years
ago, there were two separated worlds on this
planet: the East and the West. Until the fall of
the Berlin Wall in 1989, East and West
werent merely geographically expressions.
Almost every country on the globe had taken side,
willingly or not. The Cold War raged over the
world for almost 45 years and it was often far
from cold in many Asian, African, Middle Eastern
and South American countries.
The separation of these two
worlds was nowhere more visible than on the
border between Western Europe and the Soviet
Union, the co-called Iron Curtain. It was a
border that few were allowed to cross and
on-the-spot intelligence gathering was a very
risky business. Consequently, for decades, little
was known about the opponent and huge efforts
were made to retrieve even the smallest piece of
military, political or economical information
from 'the other side'. These were the heydays of
espionage, intelligence agencies and SIGINT
organisations.
Both the West and the Soviet
Union had build up huge armies with an enormous
arsenal. The skies were crowded with various
signals and SIGINT was an ideal method to collect
information from a relatively safe
distance. Huge resources and a lot of money were
spent to intercept each others signals. Both
sides deployed many mobile and fixed intercept
stations.
Eavesdropping on the Enemy
The content or
technical information behind some signals could
be read or analysed immediately, but much of the
intercepted information could not be read because
it was encrypted. The introduction of digital
systems made possible the development of far more
complex encryption schemes.
Nevertheless, both the Western countries
and the Soviets still had their successes. A key
factor in breaking encrypted signals was to
collect enough data. More data means more
statistical information for the mathematicians
who attack the codes. Both the United States and
the Soviet Union had plenty of the brightest
mathematicians. Now they just needed plenty of
data. No problem.
There were two major western
alliances who shared SIGINT intelligence during
the Cold War, and they are still active today.
The first one started as UKUSA agreement, a
cooperation between the United Kingdom and the
United States to share SIGINT intelligence during
WW2. Australia, Canada and New Zealand later
joined the alliance to form the so-called Five
Eyes (FVEY).
The second western SIGINT
cooperation is a secret European alliance between
Germany, the Netherlands, France, Denmark and
Sweden, codenamed MAXIMATOR. An important source
of their intelligence was the breaking of
encrypted communications, secured by Crypto AG
equipment. This seemingly independent Swiss firm
was covertly owned by the Central Intelligence
Agency (CIA) and the German Federal Intelligence
(BND) and sold unnoticeable weakened crypto
equipment worldwide, enabling the
MAXIMATOR-countries to easily break these
communications.
Teufelsberg Field Station Berlin
The global intercept capabilities of the American
ECHELON system, in close cooperation with
NSAs codebreakers, are renowed. During the
Cold War, ASA and later NSA operated important
SIGINT stations in Germany, the United Kingdom
and New Zealand, some of which are still
operational. In Germany, the frontier of the Cold
War, some well known examples were the American
SIGINT Field Station Berlin on top of Teufelsberg
and ASA Det J in Schneeberg, near Czechoslovakia.
The Soviets also had their share in the
worldwide eavesdropping competition with, among
others, SIGINT stations at Lourdes in Cuba, Cam
Ranh Bay in Vietnam, near Tallinn in Estland and
in South Yemen. They also had several stations in
East Germany, such as the Yenisei and Urian
listening posts in Brocken. The GRU (military
intelligence), the KGB's 16th Directorat
(interception of communications and Signal
Intelligence) and 8th Main Directorat
(communication and cryptography) did their part
in processing the intercepted traffic. They also
operate a large satellite network for
interception and communications and have a large
number of intercept stations around the world.
Nonetheless, even some smaller
countries were more than capable. The HVA, the
East German foreign intelligence service under
control of the Ministerium für Staatssicherheit
(Stasi), was well known and feared for its
excellent espionage capabilities by human
intelligence (HUMINT) with an enormous number of
agents operating in the West. However, for
decades, their technical capabilities were
heavily underestimated.
After the dissolving of the
German Democratic Republic, it became clear that
the Stasi SIGINT directorat HA III had 25
departments, over 2000 staff officers and some 80
installations in East Germany. They monitored
shortwave transmissions and more than 30,000 West
German telephones from military, diplomatic and
intelligence personnel from both West Germany and
NATO. They eavesdropped on radio signal paths
(telephone) used by the Federal Post Office, and
on VHF radios of the BND (West German
intelligence) surveillance teams. Virtually all
West German satellite-based telephone, Telex,
fax, and data transmissions were monitored.
Short range signals (VHF, radar, missile
guidance) often required interception from closer
distances. Airborne SIGINT and ELINT platforms
constantly patrolled close to and often even
beyond enemy borders to eavesdrop on their
signals . These were most dangerous missions,
even in peacetime. Many of the crews never
returned home.
The
shootdown of a C-130 above Armenia in 1958 and an
EC-121 above the Sea of Japan in 1968 are only a
few well known of over 40 U.S. aircraft that were
lost. These reconnaissance programs were top
secret and the public usually never knew about
these losses. Other welll know U.S. SIGINT
platforms were the RC-135, the EA-3B and EA-6B.
The famous Soviet TU-95 and TU-142 were also
known for their regular testing of the limits at
the NATO borders.
SIGINT collection by ships was
just as hazardous, with the capture of AGER-2 USS
Pueblo by North Korea in 1968 being the most
notorious and most damaging for U.S.
communications security. The Soviet spy trailers
were also regular visitors in Western coastal
waters. Some naval SIGINT operations were most
daring. In 1971, during operation Ivy Bells, the
nuclear U.S. submarine USS Halibut placed a 6 ton
weighing wiretap on an undersea communications
cable in the Sea of Okhotsk.
AGER-2 USS Pueblo SIGINT vessel
in 1967
The cable
connected the Soviet naval submarine base in
Kamchatsky, north-east of the Kuril Islands, with
Vladivostok Fleet headquarters. The Sea of
Okhotsk was Soviet territorial waters, forbidden
for foreign ships, heavily protected and a
playground for numerous Soviet surface and
subsurface naval exercises. Not quite a friendly
environment for U.S. submarines. Similar Soviet
submarine SIGINT missions undoubtedly remain
hidden in Russian archives.
Mysterious Cold War Signals
Often, the secrets behind
unreachable signals were unveiled, either by
ELINT, COMINT or espionage. However, despite huge
efforts and risks, some signals remained
unidentified and some of them even rose to the
stardom of mysterious Cold War signals. These
signals also caught the attention of both
Intelligence organisations and civilian radio
amateurs. There was much speculation about the
purpose of these signals, some of which were in
voice or Morse, others were strange analogue or
digital transmissions that lasted for decades.
Once such station was nicknamed
the Russian Woodpecker, because of its
characteristic repetitive tapping noise. The
Woodpecker's annoying high-power signal (an
estimated 10 Megawatt) switched between different
shortwave frequencies and disrupted legitimate
utility and amateur broadcasts all over the
world. The broadcast started in 1976 and
continued for 10 years. For decades, its purpose
remained unknown to the general public.
After the fall of
the Soviet Union it was confirmed that the
strange signal originated from an
over-the-horizon (OTH) radar as part of the
Soviet Anti Ballistic Missile early warning
system. The Soviet Duga-1 OTH system comprised
two tranmitter antennas at the Liubech-1 military
site near Chernihiv and two receiver antennas at
the Chernobyl-2 military site near Chernobyl,
Ukraine.
The
Chernobyl-2site was codenamed Steel Yard by
Western military intelligence, who managed to
photograph the site during the Cold War. The
Chernobyl-2 installation was damaged during the
1986 Chernobyl disaster and never became
operational again. The site now lays within the
18 miles Chernobyl exclusion zone, adding to its
mystery status.
They also had the Duga-2,
located in the far east of the USSR, with the
transmitter in Lian and receiver in Bolshya
Kartel . The first experimental OTH radar, simply
called Duga without number, was located near
Mykolaiv, close to the Black Sea.
The United States also had
their part in long-distance snooping by
developing the MELODY system, a so-called
bistatic interception that uses objects like the
Soviet's own missiles, or even the moon, to
reflect radar signals over very large distance,
far beyond the horizon. This enabled tracking and
analysis of remote radar locations inside Russia
Receiver antennas at the
Chernobyl-2 site, part of Duga-1
with the "woodpecker"
transmitters at Liubech-1
site
Another famous Soviet signal
is known under its call-sign UVB-76. The station,
nicknamed the Buzzer, started broadcast in 1982
with a two-second beep tone and switched, after a
decade of operation, to a monotonous 25 buzz
tones per minute. Continuously, every hour, every
single day, year after year. The station is
extensively observed by radio amateurs (without
doubt an equally monotonous job) and only a
handful of voice conversations were ever recorded
in its 28 years of operation. Its call-sign
UVB-76 was revealed during one of its rare voice
conversations. The station, which apparently
relocated in 2010, is currently known under its
new callsign UVB-76 / MDZhB. The purpose of The
Buzzer remains unknown until today.
Some believe that the Buzzer simply
occupies certain frequencies to have them
available in case of a crisis or war. Others
believe that the uninterrupted signal is part of
the notorious so-called Dead Hand, an autonomous
launch system for clusters of nuclear missile
sites that supposedly would be activated if the
signal was interrupted, due to elimination of
Soviet military command by an American first
strike. As we now know, the dead hand systems did
actually exist, but the relation between UVB-76
and the doomsday system is nothing more than pure
speculation. Nevertheless, the few interrupts of
the signal did raise some eyebrows at the time.
Another true Cold War icon is,
of course, the notorious numbers station. These
stations broadcast streams of numbers or letters
in voice or Morse, and these unlicensed and
officially non-existing stations are transmitting
since many decades. During the Cold War, there
was much speculation by radio amateurs who
intercepted these mysterious messages. Some
believed these were spy stations, but governments
denied their existence or claimed them to be
weather signals, buoys or beacons. Today,
theres plenty of evidence, from spy case
court documents and archives, that they are
indeed encrypted messages, send by intelligence
agencies to their agents in the field. Mostly,
these messages are encrypted with the unbreakable
one-time
pad. Although the Cold
War officially ended, there are still many active
numbers stations and new keep popping up, sending
messages in many different languages. Who is
listening to them remains a mystery. More about
numbers station is found on this page.
Cold War of Words
The Cold War was
not limited to military communications, signals
intelligence and spy radios but was also an open
battle of words. Some countries with opposing
ideologies imposed severe restrictions on free
travel, media and freedom of expression. Radio
signals however travelled freely across their
borders.
The problem of
information dissemination during the Cold War was
resolved by using powerful shortwave transmitters
that, according to one side, spread truthful
political information to people who were denied
free press and, according to the other side,
harmful propaganda to turn the population against
their government. This also included political
and psychological warfare operations, known as
Psy Ops. Both East and West used these methods
and rhetoric. Some of these radio stations became
true Cold War icons.
Radio Free Europe (RFE) and
Radio Liberty (RL) are United States funded
organisations, created in 1950 by the National
Committee for a Free Europe, which was in fact a
CIA front organization, created in 1949 to spread
American and Western influence and counter the
Soviet expansion. Over the years, RFE expanded
its reach to most Eurasian countries. Radio
Liberty started in 1951 and focussed on the
Soviet Union. RFE and RL had transmitter sites in
Lampertheim, West Germany, later supplemented by
transmitters in Portugal and Taiwan. Their
mission was to provide an alternative to the
targeted countries, with news and free press that
was not available behind the Iron Curtain. Over
the years, RFE and RL have broadcast in 54
different languages of the targeted countries and
regions.
Radio Free Europe transmitter
site West Germany
Voice Of America (VOA) is another major western
radio station, established in 1942 during World
War II to spread war news. VOA started
broadcasting towards Russia in 1947 to counter
Soviet propaganda against American leaders. VOA
later extended its range to all Warsaw Pact
countries. Another method to reach the public in
the Eastern Bloc were more than 300.000 balloons
with leaflets, books and posters, criticizing the
communist regimes and supporting dissidents. A
practice still used between South and North Korea
to this day.
The
Soviets, their satellite countries and other
communist countries of course countered the
Western aggression and expansion with their own
means. Radio Moscow World Service was the
official broadcast station of the Soviet Union.
Their foreign service broadcasting started in
1929 with transmitters in Moscow and Leningrad,
and later also relay stations in Vladivostok and
Magadan, with regular programs in Europe, the
Middle East, North and South America. By 1945
they reached whole Eurasia. Over the years, their
reach spread across the world with transmitters
in the Soviet Union, Eastern Europe and Cuba, and
they broadcasts in more than 70 languages. Radio
Moscow changed its name in 1993 into Voice of
Russia and renamed it again in 2014 into Radio
Sputnik. More countries joined the battle of
words. China started international broadcasts
through Radio Peking in 1950, renamed it into
Radio Beijing in 1983 and is now known as China
Radio International.
The Cuban radio station Radio
Rebelde, created in 1958 by the revolutionary
army, was supervised by Che Guevara. Transmitting
from Sierra Maestra, Radio Rebelde reached many
south American countries, relayed messages to
rebel states and eventually also targeted the
United States and the Caribbean. The official
Radio Havana Cuba (RHC) started in 1961. The
shortwave station relayed and broadcast to
countries in Europe, the Mediterranean, Africa
and the Americas, and this in eight languages. As
a communist ally of the Soviet Union, the Cubans
were allowed to use transmitters from Radio
Moscow to broadcast in Europe and the
Mediterranean. RHC was also used by Cuban
intelligence to support espionage operations in
South America and the United States, and is known
to broadcast numbers station
messages.
Cold War propaganda and
political warfare were not appreciated by the
leaders of the targeted countries but no barbed
wire, high fence or border guard could stop radio
signals from travelling across their borders. A
common practice to prevent these broadcasts from
reaching their populations was radio jamming. To
disrupt the powerful shortwave radio stations,
they used even more powerful jamming
transmitters, up to 500.000 Watt, with various
interference signals such as noise, non-stop
music or even recorded voices played backwards.
More on this on the blog post Cold War Radio
Jamming.
Radio Moskou (now
Sputnik), Radio Havana Cuba, Voice of America and Radio Free Europe became true Cold War icons and are
still in the air today. Propaganda remained
important throughout the Cold War and continues
to be relevant to this day, as it extended to
television networks and Internet. Below are also
some recording from Voice of America and Radio
Moscow, but bear in mind that these stations had
specific propaganda purposes and might not
portrait the facts accurately. Also read the blog
post Radio Moscow and
the Cold War.
Sounds of the Cold War
How did the Cold War over radio waves
actually sound like? Below some samples of intercepted
signals, accompanied by a short description. Click the
icons or the links to listen. You will notice that some
sounds are very mysterious and, given the paranoid mind
set during the Cold War, must have sounded pretty scary
at the time. The most intriguing of all is that the end
of the Cold War did not end this war of the waves. In the
contrary, the Cold War is merely replaced by a Cold
Peace, with a flourishing world of mysterious of signals.
A shortwave receiver with a good antenna was, and still
is, all you need to discover innumerable signals.
Click the mp3 icon to listen in a new
tab or the link to download.
Czech lady
Numbers station from the former Czechoslovakian
StB (State Security Service). A well recognizable
introduction signals was followed by the actual
message, mostly encrypted with the unbreakable
one-time pad system
Stasi gong station This is one of the most sinister
numbers station ever, operated by the East German
Stasi. The station with its very recognizable
weird gong sounds transmitted nearly a decade and
suddenly stopped in may 1990, in the last months
of East Germany's existence.
Attencion Station Numbers station of the Cuban
intelligence service DG. These stations remain
very active to this day. Several Cuban agents,
receiving orders through these stations, were
arrested in the United States. The most recent
spy case was in 2009.
Russian Male
Unidentified Russian language numbers station
Believed to be a transmitter operatied by the
KGB.
Woodpecker
Soviet Duga-1 system with tranmitter at Liubech-1
and receiver at Chernobyl-2. Its very powerful
signal disrupted radio communications all over
the world. According to the former commander of
the Chernobyl-2 site, the installation was
damaged during the 1986 Chernobyl disaster and
never became operational again.
The Buzzer
Soviet UVB-76 transmitter, sending its monotone
buzz tones for several decades. The purpose of
The Buzzer has never been disclosed. According to
some sources, the transmitter site was located
near Povarovo, 25 miles north-west of Moscow, but
relocated in 2010.
ELBRUS
Analogue T-217M voice encryption system from the
former East German NVA (Nationale Volksarmee).
Sound sample from Der SAS- und Chiffrierdienst.
For more information about East German equipment,
please visit Der SAS- und Chiffrierdienst website and select "Technik"
pages.
Radio Moscow 1962 radio show - Soviet first lady Nina
Khrushchev answers letters from American women.
From the NYC Municipal Archives WNYC
Collection/NYPR Archives WNYC archive.
Radio Moscow 1968 news - Crisis in Czechoslovakia and
invasion Soviets and Warsaw Pact forces to crush
counter-revolutionary forces.
From the Shortwave Radio Audio Archive SRAA archive
Radio Moscow 1968 news - Soviet request withdrawal
Israeli troops, resolving the crisis in Vietnam
and American aggression.
From the Shortwave Radio Audio Archive SRAA archive
Radio Moscow 1981 news - Martial law declared in Poland
and Soviet view on situation Polish crisis
From the Shortwave Radio Audio Archive SRAA archive
Voice Of America 1984 news - Hijacking in Tehran, Bhopal
disaster, negotiations in the Middle East, Polish
political prisoners released, etc.
VOA - U.S. Government Agency Public Domain
1984-12-08 Internet Archive
Voice Of America 1986 news - Night Line Africa with Lebanese
kidnapping, clash Chad and Lybian troops,
ceasefire in Sudan
From the Shortwave Radio Audio Archive SRAA archive
Voice Of America 1989 news - Murder in New Caledonia, space
shuttle Atlantis, talks short range missiles,
Jaruzelski pardons activists, etc.
VOA - U.S. Government Agency Public Domain
1989-05-09 Internet Archive
Radio Berlin International 1990 news - Final broadcast of RBI, marking
the end of both the station and the existence of
East germany.
From the Shortwave Radio Audio Archive SRAA archive
More on this website
Numbers
Stations What are
numbers stations, who uses them and how are these
spy transmitters operated.
One-time
pad The complete story
of one-time pad encryption and how it works.
Cuban Agent
Communications Paper
on numbers stations and operational methods of
the Cuban intelligence service.
SWL Shortwave
Listening An
introduction into how to receive shortwave
stations and the equipment you need.
TEMPEST The origin of TEMPEST, the supression
of spurious signals