Homepage
Crypto
Index
Glossary
Enigma
Hagelin
Fialka
Nema
Voice
Hand
OTP
EMU
Mixers
Phones
FILL
Codebooks
Algorithms
USA
USSR
UK
Yugoslavia
Ascom
AT&T
Bosch
Datotek
Gretag
HELL
ITT
Motorola
Mils
OMI
Philips
Racal
Siemens
STK
Tadiran
Telsy
Teltron
Transvertex
TST
Spy radio
Burst encoders
Intercept
Covert
Radio
PC
Telex
People
Agencies
Manufacturers
• • • Donate • • •
Kits
Shop
News
Events
Wanted
Contact
About
Links
   Click for homepage
Racal MA-4083
FILL Gun

The Racal MA-4083 was a hand-held electronic device that was used for transferring crypto-keys and frequency channel data to some Racal military radio sets, such as the PRM-4720A tactical VHF/FM radio [1]. The MA-4083 itself should be filled by an MA-4073 programming device.

The image on the right shows a typical MA-4083 fill gun. The device is small and leightweight, and easily fits in the pocket of a uniform. All I/O is at the top surface. There is a 7-pin socket for connection to a radio set, two LEDs (marked ON and NR), and a recessed ZEROIZE button.

Over time, improved versions of the device were issued, resulting in the addition of a letter to the model number. The MA-4083B is required for the PRM-4720A tactical radio. The device shown here is the C-version, which was used with the PRM-4515 Cougar radio and the MA-4777 unit.
  
MA-4083G fill gun

The MA-4083 can hold up to 30 separate transmit and receive frequencies, allowing split-frequency operation, or 4 cryptographic keys, but not both types of information at the same time. In practice, the MA-4083 was often deployed in pairs: one for frequencies and one for keys. An internal battery retains the data when the device is not in use, but this battery is not used for operation of the MA-4083. Instead, the unit is powered by the device to which it is connected.

MA-4083G fill gun Bottom view Top view MA-4083G fill gun Close-up of the connector, the indicators and the ZEROIZE button Lifting the zeroize flap Lifted zeroize flap Pressing the zeroize button

Versions
Different versions of the MA-4083 exist, each of which is identified by a single letter suffix to the model number, for example: MA-4083C. Note that different versions have to be used for different encryption modules. Using the 'wrong' version, allows the frequencies to be programmed, but not the cryptographic keys. Always check the documentation of the radio before trying to load the keys. In most cases, a single letter suffix to the radio model tells you which programmer to use.

  • MA-4083B
    This version was used with the PRM-4720A tactical VHF/FM radio [1].

  • MA-4083C
    This version should be used with radios or encryption units that have a part number with the suffix 'S'. Typically, these are the units with a green MA-4437 crypto modules.

  • MA-4083G
    This version should be used with radios or encryption units that have a part number with the suffix 'U', for example PRM-4515H3TCU. Typically, these are the units with the red MA-4487 crypto module.
Data types
The MA-4083 can store the following data in its internal memory:

  • 30 Transmit and 30 Receive frequencies, OR
  • 4 Cryptographic keys

Programming   MA-4073
Before the MA-4083 can be used to fill a radio or crypto device, the unit itself has to be filled with either channel frequency data, or crypto­graphic keys. This is done with the MA-4073 programmer as shown in the image on the right.

Note that for transferring crypto keys, the the model number of the programmer must have the same suffix as the model number of the fill gun (e.g. MA-4073C and MA-4083C). Frequency data can be programmed with any model.

 MA-4073 Programmer
  
Loading data from the programming into the fill gun

Zeroizing
In order to prevent the keys from falling into the wrong hands, they can be purged instantly by ZEROIZING it. This is generally a two-fold operation. In this case, it involves lifting a spring-loaded flap and pressing the Z-button.

Note that the device does not have to be powered for a zeroize action. This can be done with an unconnected device. The device is usually also zeroized when it is stored for an extended period of time. Once zeroized, the device goes into power-save mode, so that its internal battery lasts longer.
  
Lifted zeroize flap

Loading data from the programming into the fill gun Lifting the zeroize flap Lifted zeroize flap Pressing the zeroize button
Help required
If you know about other radios that are compatible with this fill gun, or if you have any information that is not listed here, please contact us.

Documentation
  1. Racal, MA 4083C leaflet
    Date unknown. Retrieved May 2014 [2].

  2. Racal Radio Ltd., MA 4073C and MA 4073G Programmer, User Handbook
    Ref. TH 8224. Issue 3. June 1995. Appendix A (3 pages).

  3. Racal-Tacticom Ltd. Fill Gun MA 4083G, Technical Manual
    Ref. A 3030. Issue 1. April 1995.
References
  1. Jane's Military Communications, PRM4720A tactical VHF/FM...
    Retrieved from webite, June 2012.

  2. Dave McKay (G1JWG), Racal Cougar and Cougarnet Radio System
    Retrieved May 2014.
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: Sunday 29 July 2012. Last changed: Tuesday, 26 January 2016 - 21:00 CET.
Click for homepage