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.
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 . At that point, the
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 .
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 .
A batch of another 75 units would be produced elsewhere .
A few years earlier (1974) the automatic 20 Watt 3-30 MHz version RT/B-59
had been developed.
According to the Stasi (MfS), the radio set was used by the
Military Intelligence (MI) of the US Army .
Stasi = Staatssicherheit (state security).
Also known as MfS (Ministerium fur Staatssicherheit).
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).
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.
The image above was found in the archives of the former
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
during the Cold War.
According to a hand-written Stasi note,
it came from the American secret service INSCOM 1 .
INSCOM = US Army Intelligence & Security Command.
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.
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
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
and the burst encoder controls the transmission.
At the center of both short sides are circular moisture-resistant
of the transmitter provided 10 Watts (RT-59A) or
even 20 Watts (RT/B-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.
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
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
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
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.
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
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.
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
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
Frequency3-16 MHz (4 ranges)
Ranges3-5 MHz, 5-8 MHz, 8-12 MHz and 12-16 MHz
Power5W (10W on the RT-59A, 20W on the RT/B-59)
Dimensions105 x 38 x 63 mm
Frequency3-24 MHz (3 ranges)
Ranges3-6 MHz, 6-12 MHz and 12-24 MHz
Dimensions100 x 45 x 22 mm
CO/B-8Alphabet encoder (MX-4496) 1
KE-8BKeyer (KY-468) 1
CA/A-3BTape cartridge (MA-9) 1
HG/B-59Hand-cranked power generator
CC-59Carrying case 2
RT/B-59Automatic 20 Watt 3-30 MHz transmitter
RT-59A10 Watt version of the RT-59
Part of the CK-8 burst encoder.
Introduced in November 1975 .
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.
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  above. The documents are referenced
in the text as [4.1] - [4.2] - etc.
- Research & Development Laboratory, May 1966
- Monthly Narrative Summary Report - June 1976
CIA Memorandum, 1 July 1976, page 4. OCE-M76-284.
- CIA Equipment Board Minutes
13 October 1967. Page 2, point B.1.
- CIA Equipment Board Minutes
8 November 1967. Page 3.
- CIA, Covert Engineering Division
1 January - 31 March 1974.
- Monthly Narrative Summary Report - April 1975
CIA Memorandum, 5 May 1975. Page 1.
- Monthly Narrative Summary Report - May 1975
CIA Memorandum, 5 June 1975. Page 3.
- Monthly Narrative Summary Report - June 1975
CIA Memorandum, 3 July 1975. Page 1.
- Monthly Narrative Summary Report - October 1975
CIA Memorandum, 5 November 1975. Page 1.
- Monthly Narrative Summary Report - July 1976
CIA Memorandum, 6 August 1976, page 4. OCE-M76-339. CONFIDENTIAL. 2
Approved for release by the CIA on 8 September 2000.
Approved for release by the CIA on 23 October 2010.
- MfS, HA II, Nr. 41374, Images of RS-59 spy radio set
Archiv der Zentralstelle, BStU 0267. Date unknown. 1
- Detlev Vreisleben, Information from MfS archives
Personal correspondence. August 2015 - October 2017.
- Louis Meulstee, Wireless for the Warrior, volume 4, Supplement, Chapter 138
July 2016. Retrieved October 2017.
- CIA, Collection of documents related to RS-59
Released under the FOIA between 2000 and 2010.
➤ See above
Document kindly supplied by Detlev Vreisleben .
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© Crypto Museum. Created: Thursday 26 October 2017. Last changed: Saturday, 12 May 2018 - 14:53 CET.