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Soviet countermeasures

During the Cold War, the Soviet Union (USSR) developed a range of miniature portable intercept receivers that were designed to be worn inconspicuously on operator's body. They were used to intercept (clandestine) communications, locate foreign agents (radio direction finding, RDF) and for surveillance. Most of these receivers were designed to be used in close proximity of the transmitter.

In addition to the portable receivers, they developed a series of high-performance stationary communication receivers and radio direction finders (RDF or DF). The receivers below are covered on this website.

Soviet countermeasures
Russian R11-PA valve-based body-wearable direction finder
Soyka body-wearable intercept receiver
Filin (A, B and V) body-wearable intercept receiver
Sinitsa body-wearable intercept receiver
Kopchik aperiodic surveillance detection receiver
Wire-line bug detector
Non-linear Junction Detector
Russian bug detector for the 100 MHz to 12 GHz range
The R11-PA is one of the first body-wearable direction finders developed during the Cold War in the Soviet Union. It is valve-based and covers a frequency range of 2.1 to 25 MHz.

The devices has a curved shape, so that it can be carried on the body, hidden under the operator's clothing. It was developed around 1954.

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R11-PA seen from the bottom

Soyka was a compact versatile body-wearable intercept receiver for the HF-bands between 700 kHz and 30 MHz, divided over 10 ranges. For each range it has a plug-in coil unit. Furthermore, two wide-band (non-selective) plug-ins were supplied.

Soyka was deployed in Russia and some other Warsaw Pact countries, and came in a compact suitcase, together with many accessories.

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Soyka intercept receiver. Click for more information.

Around 1970, the Russians developed a series of miniature portable intercept receivers that were capable of intercepting VHF/UHF AM/FM radio signals in close proximity of the transmitter. There were three models that together cover a frequency range from 24 to 308 MHz.

Filin was used extensively by the Secret Police (Stasi) of the former DDR (East-Germany), who also made some modifications to the unit.

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Filin intercept receiver. Click for more information.

Sinitsa was by far the most advanced portable intercept radio made by the Russians. It covers all frequencies between 30 MHz and 1 GHz, divided over 13 ranges and is even capable of intercepting surveillance radios with frequency hopping (FH).

The aperiodic receiver comes in a suitcase with a large number of plug-ins and accessories. It can even be used for unmanned monitoring by linking it to a telephone line.

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Sinitsa direction finder. Click for more information.

During the Cold War, Soviet and Warsaw Pact agents used the Kopchik covert surveillance detection receiver, to check whether they were being followed by their foreign counterparts.

The device is an aperiodic receiver that can detect nearby radio signals, in particular those in the 150 and 400 MHz frequency bands.

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Kopchik receiver with remote control unit, antenna and speaker

Orchidea-2 was a device that was able to find a covert listening device (bug) that was connected to a wire line, such the power network, remote door openers, telephone lines and TV cabling.

The device is usually carried in an unobtrusive Samonite-style briefcase, together with a set of ancillaries, and has a built-in oscilloscope.

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Orchidea-2 main unit

Orchidea-3 was a non-linear junction detector (NLJD), developed in the mid-1980s in the Soviet Union (USSR) and used during the Cold War as a countermeasures device by the countries of the former Warsaw Pact.

Unlike Western NLJD's, which generally use a low-power continuous wave, Orchidea-3 uses a high-power pulsed signal.

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Orchidea-3 main unit with antenna

Osobnjak was a range of high-end counter­measures receivers, developed by the Soviets for protection against resonant cavity microphones, a special kind of passive covert listening devices (bugs) that were activated by a strong RF signal.

As the Soviets were the first to employ resonant cavity microphones, they knew that sooner or later their Western counterparts would use the same technology against them.

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