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Covert surveillance detection receiver - wanted item

SRR-100 was a covert body-worn receiver or scanner, developed and built in the 1970s by an unknown manufacturer for the US Central Intelligence Agency (CIA). It was used curing the Cold War for intercepting the radio communications of Soviet and other Eastern Block surveillance teams. The SRR-100 consists of a small pocket receiver, a neckloop and a wireless earpiece.

The receiver measures approx. 7 x 11 x 1.5 cm. It has two knobs at the top, one for controlling the volume and one for setting the frequency, plus a LEMO socket for connection of a neck­loop. At the bottom is a circular screw that gives access to the battery compartment. The unit is probably powered by two AA-size battery cells.

The neckloop serves two purposes: it is used as the antenna, and as an inductive loop or coil for delivering audio to the wireless Phonak earpiece.

The receiver is capable of intercepting any radio traffic within its vicinity, and was usually carried in a soft holster under the operative's clothing. Covert CIA operatives used it in countries like Russia and the DDR (East-Germany) to ensure that they were black, which means that they were free from surveillance by their adversaries.

The image on the right shows a close-up of the SRR-100 as described in surviving MfS (Stasi) 1 reports about confiscated US covert equipment.

The SRR-100 is similar to the Russian Kopchick receiver, which serves the same purpose. It was developed around the same time as the SRR-100, but it is currently unknown who was first. The SRR-100 seems to be the more advanced one, as it uses a wireless Phonak earpiece.
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Help required
We are looking for detailed information about the SRR-100 receiver and, if possible, a working unit. If you can provide any of these, or any other information, please contact us.

  1. Ministerium für Staatssicherheit (MfS), commonly abbreviated to Stasi, was the repressive intelligence and secret police organisation of the former DDR (East-Germany).  More

Complete set
The image below shows a complete SRR-100 kit, consisting of the SRR-100 receiver unit (left), a neckloop that acts at the antenna and as inductive audio coil, a white cloth holster or body harness, a phonak earpiece and a set of spare hearing aid button-type batteries for the earpiece. The photograph is taken from Stasi reports about confiscated equipment [2]. Click to enlarge.

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Equipment in Moscow
The image below shows the kind of equipment that has been confiscated from US agents by the Russian KGB (now: FSB) during the Cold War [1]. At the rear left, just in front of the leftmost radio set, is an SRR-100 receiver. Click the image for a close-up. The SRR-100 was probably recovered from CIA case officer Martha Peterson when she was arrested on 15 July 1977 after making a dead drop for the Russian spy Aleksandr Dmitrievich Ogorodnik, codenamed TRIGON.  More

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Detection runs in Moscow
The online magazine WIRED has made an interesting series of YouTube videos, in which Joanna Mendez — former CIA Chief of Disguise of the Office of Technical Service (OTS) of the CIA — talks about some of the tactics and gadgets they used during the Cold War. In the episode below she explains how the SRR-100 receiver was used during surveillance detection runs in Moscow [3].

Former CIA Chief of Disguise Joanna Mendez explains how the SRR-100 was used [3]

Soviet equivalent
In the 1970s, the Soviet Union (USSR) introduced its own surveillance detection receiver, which was also body-worn and was able to detect a wide range of nearby radio signals, in particular those in the 150 and 400 MHz bands.

The image on the right shows the Russian device, which was known as Kopchik (Копчик).

 More information
Kopchik receiver with remote control unit, antenna and speaker

The SRR-100 set consists of the following parts:

  • SRR-100 receiver
  • Phonak earpiece
  • Neckloop
  • Batteries
  • Harness
  1. Unknown author, Photograph of CIA equipment found in Moscow
    Date unknown. 1

  2. MfS, Photographs of SRR-100 device
    MfS - HA II, Nr. 42925, BStU 0242-0243. 1

  3. Wired: Former CIA Chief of Disguise Breaks Down Cold War Spy Gadgets
    25 November 2020.
  1. Document kindly supplied by Jörg Drobick.

Further information
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Crypto Museum. Created: Wednesday 18 January 2017. Last changed: Thursday, 26 November 2020 - 09:57 CET.
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