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RS-59
Modular spy radio station

RS-59 is a modular short-wave (SW) spy radio set, developed in the late 1960s by the technical services division (TSD) of the US 1 Central Intelligence Agency (CIA). The set consists of an RR-59 receiver, an RT-59 transmitter, a CK-8 burst encoder and several interfaces and accessories. Although detailed information about this set is unavailable, it is known from Stasi 2 archives that a complete station was captured during the Cold War in the former DDR (East-Germany) [1].

The RS-59 was a low-power mid-range radio station, intended for distances up to 600 miles. It was supplied complementary to the existing long-range RS-49, which had a higher output power. The RS-59 was fully developed in-house by the CIA and was built by the CIA and others.

The image on the right shows the RT-59 trans­mitter, which is the only part of the RS-59 set that is currently held in the collection. The unit measures 105 x 38 x 63 mm and weights just 328 g. All connections (except for the antenna) are via the slide connector at the front right.
  
RT-59 transmitter

Development and improvement of the RS-59 took place over a period of 10 years, from 1966 to 1976. The RR-59 receiver was the first unit to be released, with prototypes being available in May 1966 [4]. At that point, the RT-59 transmitter and the rest of the RS-59 station was 'expected soon'. In order reduce the number of interconnection cables, a new type of high-quality low-profile slide connector was developed at the same time, by an (unknown) external party [4].

In the following years, production of the components of the RS-59 radio set, was delayed several times due to shortages in electronic parts. Furthermore the components were improved several times, leading to additional identifiers in the model number, e.g. RR/C-59 and RT-59A.

In 1976, 10 years after the introduction of the set, the RT-59 transmitter was succeeded by the improved RT-59A, that offered an output power of 10 Watts. By June 1976, the first 30 units had been produced in-house by the CIA, with 50 more underway, complemented by the purpose-built CC-59 carrying case [4]. A batch of another 75 units would be produced elsewhere [4]. A few years earlier (1974) the automatic 20 Watt 3-30 MHz version RT/B-59 had been developed.

  1. According to the Stasi (MfS), the radio set was used by the Military Intelligence (MI) of the US Army [1].
  2. Stasi = Staatssicherheit (state security). Also known as MfS (Ministerium fur Staatssicherheit).  More

RT-59 transmitter
RT-59 transmitter
Antenna terminals and tuning controls
Crystal socket
MODE selector
Multi-way slide connector
Membrane
RT-59 with case shell removed
A
×
A
1 / 8
RT-59 transmitter
A
2 / 8
RT-59 transmitter
A
3 / 8
Antenna terminals and tuning controls
A
4 / 8
Crystal socket
A
5 / 8
MODE selector
A
6 / 8
Multi-way slide connector
A
7 / 8
Membrane
A
8 / 8
RT-59 with case shell removed

Complete setup
The diagram below gives an overview of all components that form the RS-59 spy radio station. The left half consists of the actual parts of the radio set, whilst the right half shows the CK-8 burst transmitter that was used to send pre-encoded messages at very high speed, in order to minimise the risk of interception and discovery by means of radio direction finding (RDF).

Complete RS-59 spy radio station. Click for a better view. Photograph retrieved via [1][2].

The units of the RS-59 radio set (left) are interconnected by means of sliding contacts at one of the sides of each module. These contacts are clearly visible on the battery pack and the mains PSU at the front left. The RR/C-59 receiver was sometimes supplied as a stand-alone receiver.

Complete RS-59 set in briefcase. Click for a better view. Photograph retrieved via [1][2].

The image above was found in the archives of the former Stasi (MfS). It shows a regular briefcase in which an RS-59 radio station, complete with CK-8 burst encoder (GRA-71) and cabling, is stored in cut-outs of a protective foam inlay. It was confiscated in the DDR during the Cold War. According to a hand-written Stasi note, it came from the American secret service INSCOM 1 [1].

  1. INSCOM = US Army Intelligence & Security Command.  Website

Parts
RT-59 transmitter
RR-59 receiver
AN/GRA-71 burst encoder/transmitter
Controls on the top surface of the RT-59 transmitter


Transmitter   RT-59
The transmitter measures 105 x 38 x 63 mm – roughly the same side as the receiver – and weights 328 grams. It produces a maximum output power of approx. 5 Watts and covers a frequency range of 3-16 MHz, divided over four bands, selectable with the BAND-selector.

The image on the right shows a typical RT-59 unit, as it was designed in 1966. At the top left are two spring-loaded terminals for connection of a wire antenna (ANT) and a suitable counter­poise (GND). The 4-position LOAD-selector to the right of the antenna terminals is used to choose the optimum matching of the antenna circuit, using the small meter as an indicator.

A suitable HC-25/U crystal can be installed in the 2-pin socket at the front right, whilst the BAND selector is set to the corresponding frequency range: 3-5, 5-8, 8-12 or 12-16 MHz.
  
RT-59 transmitter

At the top right is the MODE switch. In the lowest position (RECEIVE) the receiver is enabled (via the PSU). In the center position the transmitter is enabled, but does not directly produce a signal. In this position, the transmitter is under control of the burst transmitter. In order to adjust the transmitter for maximum output power, push (and hold) the switch into the KEY position and adjust TUNE (at the bottom left) for maximum power, using the miniature meter as an indicator.

The construction at the right of the front surface is a purpose-designed 10-way slide connector that mates with a similar connector on the PSU. Via this connector, power is provided to the transmitter, the transmitter controls the receiver and the burst encoder controls the transmission. At the center of both short sides are circular moisture-resistant pressure membranes. Later versions of the transmitter provided 10 Watts (RT-59A) or even 20 Watts (RT/B-59) [4].

Receiver   RR-59
The receiver measures 100 x 45 x 22 mm. It supports up to 10 crystal controlled channels that are pre-installed under a removable lid at the left of the control panel. The actual frequencies are written on a label on the lid. Furthermore, an external crystal can be fitted to the socket at the front left, in which case the 11-position channel selector (to the right of the socket) is set to 0.

The device has a 2-pin socket for connection of the supplied earphones, and two wire terminals for connection of the antenna and counterpoise (ground) at the top right. The receiver covers a frequency range of 3 to 24 MHz, divided over three bands. The band selector (at the front right) is also used as the power switch. In the leftmost position, the receiver is turned OFF.

The knurled knob at the right (TUNE) is used for tuning the RF circuit to the selected frequency. The remaining two knobs are for volume (GAIN) and for Beat Frequency Oscillator (BFO) setting.
  
RR/C-59 receiver

Although this is not visible in the image on the right, it is believed that power should be supplied to sliding contacts at the rear of the unit. The receiver could be powered directly by the battery or the mains PSU (stand-alone), or via the RS-59 interface unit (as part of the complete station).

Burst encoder   CK-8
In order to minimise the risk of interception by enemy monitoring stations, or discovery by means of radio direction finding (RFD), it was common practice to be on the air as short as possible, by using a so-called burst encoder in combination with a burst transmitter (also known as a keyer).

The RS-59 came with a CK-8 keyer/coder, the CIA version of the well-known GRA-71. It uses a magnetic tape cartridge on which a pre-encoded (commonly encrypted) message was recorded by means of the CO/B-8 letter encoder shown here.

For this, a CA/A-3B tape cartridge was attached to the magnetic head of the encoder. The alphabet dial was then set to the first letter of the message, after which the handle was pulled. The letter was then recorded onto the magnetic tape. This procedure was repeated for each letter, until the entire message was recorded.
  
CO/B-8 Alphabet Coder

Once the message was recorded (encoded) onto the tape, the tape was attached to the KE-8B keyer, which in turn was connected to the RT-59 transmitter via the small AA-59 interface (and the RS-59 unit). After rewinding the tape and winding-up the spring mechanism of the keyer, a button was pressed to send the recorded message at high speed, known as a burst transmission.

 More about the CK-8

Stay-behind version of the GRA-71 burst encoder
CO/B-8 Alphabet Coder
Closed Tape Cartridge
CA-3B Tape Cartridge
Attaching the tape cartridge to the Alphabet Coder
Operating the handle
Placing the Tape Cartridge on the Keyer
Keyer rear panel
B
×
B
1 / 8
Stay-behind version of the GRA-71 burst encoder
B
2 / 8
CO/B-8 Alphabet Coder
B
3 / 8
Closed Tape Cartridge
B
4 / 8
CA-3B Tape Cartridge
B
5 / 8
Attaching the tape cartridge to the Alphabet Coder
B
6 / 8
Operating the handle
B
7 / 8
Placing the Tape Cartridge on the Keyer
B
8 / 8
Keyer rear panel

Interior
The transmitter consists of a frame that is milled out of a solid piece of aluminium, of which the front panel forms an integral part. The unit is enclosed in an aluminium case shell, that is held in place by three recessed screws: one at the bottom, one at the front and one at the right side.

Once these three screws have been removed, the case shell can be taken off. This may require a bit of force, as the shell can be bound due to the use of thick conformal coating inside the device.

Once the case shell is removed, the interior is exposed, as shown in the image on the right. At the left is a printed circuit board (PCB) with most of the electronic parts. The right half holds the controls, the power amplifier (PA) transistor and some passive components. At the front right is the antenna matcher, that consists of a multi-tap toroid coil and an adjustable capacitor.
  
RT-59 interior

The taps of the toroid coil are connected to the 4-position band selector on the control panel, whilst the capacitor (TUNE) is used for maximising the efficiency of the tuned circuit, and hence the transmitter's power output. At the right right is a miniature relay that is used to switch between transmit and receive, under control of the 3-position MODE switch at the control panel.

RT-59 with case shell removed
RT-59 interior
RT-59 interior
Top view
Antenna tuner
Detail
Relay
PA transistor
C
×
C
1 / 8
RT-59 with case shell removed
C
2 / 8
RT-59 interior
C
3 / 8
RT-59 interior
C
4 / 8
Top view
C
5 / 8
Antenna tuner
C
6 / 8
Detail
C
7 / 8
Relay
C
8 / 8
PA transistor

Specifications
Transmitter   RT-59
  • Frequency
    3-16 MHz (4 ranges)
  • Ranges
    3-5 MHz, 5-8 MHz, 8-12 MHz and 12-16 MHz
  • Power
    5W (10W on the RT-59A, 20W on the RT/B-59)
  • Dimensions
    105 x 38 x 63 mm
  • Weight
    328 grams
Receiver   RR/C-59
  • Frequency
    3-24 MHz (3 ranges)
  • Ranges
    3-6 MHz, 6-12 MHz and 12-24 MHz
  • Dimensions
    100 x 45 x 22 mm
Components
  • RR-59
    Receiver
  • RT-59
    Transmitter
  • RS-59
    Interface
  • CN-59A
    ?
  • RS-59
    PSU
  • RA-59A
    Battery pack
  • CO/B-8
    Alphabet encoder (MX-4496) 1
  • KE-8B
    Keyer (KY-468) 1
  • CA/A-3B
    Tape cartridge (MA-9) 1
  • HG/B-59
    Hand-cranked power generator
  • CC-59
    Carrying case 2
Later versions
  • RR/C-59
    Receiver
  • RT/B-59
    Automatic 20 Watt 3-30 MHz transmitter
  • RT-59A
    10 Watt version of the RT-59
  1. Part of the CK-8 burst encoder.  More
  2. Introduced in November 1975 [4].

Wanted
At present, the RT-59 transmitter is the only part of the RS-59 radio set held in our collection. We would like to find the RR-59 receiver and the other parts of the RS-59 radio set, along with any documentation or manuals that might exist. If you can provide any of these, please contact us.


CIA Documents
The following documents were release by the CIA between 2000 and 2010, and contain information about the RS-59 and its components. It is a further subdivision of Reference [4] above. The documents are referenced in the text as [4.1] - [4.2] - etc.

  1. Research & Development Laboratory, May 1966
    CIA/Undisclosed party. SECRET 1

  2. Monthly Narrative Summary Report - June 1976
    CIA Memorandum, 1 July 1976, page 4. OCE-M76-284.

  3. CIA Equipment Board Minutes
    13 October 1967. Page 2, point B.1.

  4. CIA Equipment Board Minutes
    8 November 1967. Page 3.

  5. CIA, Covert Engineering Division
    1 January - 31 March 1974.

  6. Monthly Narrative Summary Report - April 1975
    CIA Memorandum, 5 May 1975. Page 1.

  7. Monthly Narrative Summary Report - May 1975
    CIA Memorandum, 5 June 1975. Page 3.

  8. Monthly Narrative Summary Report - June 1975
    CIA Memorandum, 3 July 1975. Page 1.

  9. Monthly Narrative Summary Report - October 1975
    CIA Memorandum, 5 November 1975. Page 1.

  10. Monthly Narrative Summary Report - July 1976
    CIA Memorandum, 6 August 1976, page 4. OCE-M76-339. CONFIDENTIAL. 2
  1. Approved for release by the CIA on 8 September 2000. CIA-RDP78-02820A001200030046-5.
  2. Approved for release by the CIA on 23 October 2010. CIA-RDP78-02820A001400090005-1.

References
  1. MfS, HA II, Nr. 41374, Images of RS-59 spy radio set
    Archiv der Zentralstelle, BStU 0267. Date unknown. 1

  2. Detlev Vreisleben, Information from MfS archives
    Personal correspondence. August 2015 - October 2017.

  3. Louis Meulstee, Wireless for the Warrior, volume 4, Supplement, Chapter 138
    July 2016. Retrieved October 2017.

  4. CIA, Collection of documents related to RS-59
    Released under the FOIA between 2000 and 2010.  See above
  1. Document kindly supplied by Detlev Vreisleben [1].

Further information
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© Crypto Museum. Created: Thursday 26 October 2017. Last changed: Saturday, 12 May 2018 - 13:53 CET.
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