Click for homepage
USA
CIA
  
RR/E-11 →
AT-3 →
  
AS-3
Automatic CIA agent radio set

AS-3, 1 was an American modular solid-state automatic clandestine radio station, also known as a spy radio set, developed around 1959 on behalf of the US Central Intelligence Agency (CIA). From 1962 onwards, it replaced earlier valve-based radio sets like the RS-1 and RS-6 [1][2].

Some of the parts of the AS-3 radio station

A typical AS-3 station consisted of an AT-3 transmitter, an RR/E-11 or RR/D-11 receiver, a battery pack or PSU, and a burst encoder with tape cartridges. According to an early version of the manual, it was possible to connect a printer that was suitable for HELL transmissions [u].

  1. AS = Automatic Station (as opposed to RS = Radio Station).

Parts
AT-3 transmitter
Single-band receiver
Double-band receiver
Battery pack BP-3
AC Power Supply Unit AP-3
Text printer (HELL)
Burst encoder CO-3
Magnetic tape cartridge CA-3
Transmitter   AT-3
The AT-3 transmitter is the central piece of the AS-3 spy radio set. It measures 26 x 22 x 6 cm and weights approx. 3.5 kg. It is powered by a 12DC source (10A), and produces 25W output.

At the top right is a hinged lid below which is a bay for a CA-3 tape cartridge. It allows a pre-recorded message to be played back at 300 words per minute. At the right side is a socket for the RR/E-11 or RR/D-11 receiver. At the left is a socket for a TP-3 HELL printer.

 More information

  
Original AT-3 transmitter. Source unknown. Photograph obtained via Louis Meulstee [3].

Receiver   RR/E-11
RR/E-11 was among the first solid-state spy receivers developed by the CIA Radio Lab. It was intended for use as part of the AS-3 radio set, and could be plugged into the right side of the AT-3 transmitter, in which case power (12V) and antenna signal were supplied by the transmitter.

The receiver, which was released well before the AS-3 radio station was ready, could also be used stand-alone, in which case it could be powered by a 6V or 12V DC source, whilst antenna and headphones were connected directly to the unit.

 More information

  
RR/E-11 receiver

Two-band receiver   RR/D-11
RR/D-11 was a plug-in receiver for the AS-3 radio station, that was similar to the RR/E-11 shown above, albeit with two frequency bands instead of one. The receiver is approx. 2.5 cm (one inch) deeper than the RR/E-11, but can be plugged into the same socket of the transmitter.

At present, no image of the two-band RR/D-11 receiver is available.
  

Battery pack   BP-3
For portable and mobile operation, the AT-3 could be powered by a purpose-built battery pack, designated BP-3, which plugged into the 9-pin male receptacle at the rear centre. It delivered a voltage of 12V DC at 10A.

At present, no image of the original BP-3 battery pack is available, but it is likely that it had the same width and hight as the transmitter. The depth is currently unknown.
  

AC power supply unit   AP-3
According to the original documentation, an external power supply unit (PSU) was available for powering the transmitter directly from the mains (110 - 240V AC).

At present, no image of the AP-3 power supply unit is available.
  

Printer   TP-3
TP-3 was a tape printer that could be inserted into the left side of the AT-3 transmitter. It allowed Hellschreiber signals from the RR/E-11 or RR/D-11 receiver (connected at the right side of the transmitter) to be printed on a paper strip.

It is currently unknown what the TP-3 printer looked like, and it is uncertain whether there are any surviving pictures of it. If you have additional information, please let us know.

 More information

  
Click to see more

Burst encoder   CO-3
The AS-3 radio set was probably the second US spy radio set to use high-speed morse burst transmissions to reduce the chance of detection and discovery by radio direction finding (RDF). The first one was the RS-1 which it replaced.

The CO-3 was a simple device that allowed the bare morse elements – dots and dashes – to be recorded onto a CA-3 tape cartridge. Once recorded, the tape was played back on the built-in keyer of the AT-3 transmitter.

 More information

  
CA-3 cartridge installed in CO-3 coder

Tape cartridge   CA-3
Messages – generally encrypted or otherwise coded – were pre-recorded with the CO-3 coder shown above, onto a CA-3 tape cartridge as shown in the image on the right. The cartridge contains regular magnetic audio tape of the era, and can hold up to 150 five-character words.

Recording a message was time-consuming, as each dot, dash and space had to be entered separately. But once it was recorded, it could be sent in a matter of seconds, which significantly reduced the chance of discovery by means of radio direction finding (RDF).

  
CA-3B Tape Cartridge


History
Development of the AS-3 started in 1956 and was finished in 1959 or 1960. A total of 150 receivers (RR/D-11 and RR/E-11) were procured for delivery in May 1959, and the final report was delivered in July 1959. Production of the AT-3 transmitter was halted however, but in August 1960, 10 prototypes were available, with an anticipated production run of 250 units [w].


Specifications
Transmitter   AT-3
  • Frequency
    3 - 30 MHz
  • Output
    25W
  • Supply
    12V DC / 10A
  • Dimensions
    26 × 22 × 6 cm
  • Weight
    3.5 kg
Receiver   RR/E-11
  • Bands
    1
  • Frequency
    3 - 12 MHz
  • Dimensions
    22 × 11 × 4 cm
  • Weight
    1.9 kg
Receiver   RR/D-11
  • Bands
    2
  • Frequency
    3 - 12 MHz & 12 - 30 MHz
  • Dimensions
    22 × 13.5 × 4 cm
  • Weight
    1.9 kg
Literature
  1. Development of AS-3 Portable Radio Station, Progress Report No. 1
    1 October 1956. 1

  2. Development of AS-3 Portable Radio Station, Progress Report No. 2
    1 November 1956. 1

  3. Development of the Semi-Automatic Two-Way Radio Station AS-3, Progress Report No. 3
    1 January 1957. 1

  4. Development of the Semi-Automatic Two-Way Radio Station AS-3, Progress Report No. 4
    11 March 1957. 1

  5. Development of the Semi-Automatic Two-Way Radio Station AS-3, Progress Report No. 5
    1 May 1957. 1

  6. Development of the Semi-Automatic Two-Way Radio Station AS-3, Progress Report No. 6
    1 July 1957. 1

  7. Development of the Semi-Automatic Two-Way Radio Station AS-3, Progress Report No. 8
    1 November 1957. 1

  8. Contract RD-122, Task Order 1 - AS-3
    15 November 1956. 1

  9. Contract RD-122, Task Order 1 - AS-3
    18 December 1956. 1

  10. Contract RD-122, Task Order 1 - AS-3
    7 February 1957. 1

  11. Contract RD-122, Task 1 - AS-3 - Trip Report
    18 March 1957. 1

  12. AS-3 Contract RD-122 - Trip Report
    10 May 1957. 1

  13. Trip Report - Discussions on RS-11 and AS-3 Equipment
    10 May 1957. 1

  14. Trip Report - RD-122 - AS-3
    24 June 1957. 1

  15. Trip Report - RD-122 - AS-3
    18 December 1958. 1

  16. Trip Report - AS-3
    17 April 1959. 1

  17. AS-3 Agent Communication System (Project 2108)
    13 December 1956. 1

  18. Semi-Automatic Agent Communications Set, AS-3 (Project 2108)
    30 July 1957. 1

  19. TP-3 Motors
    19 November 1957. 1

  20. Preliminary Evaluation of TP-3, Hellschreiber Transistorized Printer
    19 December 1957. 1

  21. Trip Report - AS-3 Tests (hints to Hellschreiber usage)
    23 April 1959. 1

  22. Development of a Minature DC Motor for the TP-3 printer
    30 December 1959. 1

  23. Technical Notes on AT-3 Transmitter
    26 August 1960. 1

  24. Army Evaluation of AS-3 Equipment
    5 March 1962. 1

  25. Defects in AS-3 Prototype - Attachment 'A'
    Date unknown.

  26. Suggested AS-3 Accessories
    8 May 1959. 1

  27. Conference Report, Radio Station AS-3
    19 July 1957. 1

  28. Conference Report, Radio Station AS-3
    27 May 1957. 1

  29. Conference Report, AS-3
    31 October 1958. 1
  1. Sanitized copy approved for release by CIA on 14 February 2013 — 2 April 2013.

Documentation
  1. Preliminary Instruction Manual for Radio Set AS-3
    CIA, 11 February 1959. 1

  2. RR/E-11 Receiver, Description
    Date unknown. 1

  3. AP-3A Power Supply Instruction Manual
    Date unknown. 1  Older version
References
  1. Pete McCollum, The AS-3 HF Radio Set
    Retrieved June 2020.

  2. Louis Meulstee, RR/E-11
    Wireless for the Warrior - Volume 4 Supplement, Chapter 142.
    October 2017. Retrieved June 2020.

  3. Louis Meulstee, AT-3
    Wireless for the Warrior - Volume 4 Supplement, Chapter 143.
    October 2017. Retrieved June 2020.

  4. H. Keith Melton, CIA Special Weapons & Equipment: Spy Devices of the Cold War
    New York, 1993. ISBN 0-8069-8732-4. Page 19.

  5. CIA, Request for Bids, AS-3
    30 April 1956. 1
Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Monday 29 June 2020. Last changed: Thursday, 20 April 2023 - 13:53 CET.
Click for homepage