Listed here are systems or security initiatives which I located on the Internet:

Automanual System (AMS)


BRUIN - Bruin was a British trunk communications system that extended telephone and data services to major headquarters units down to brigade level.  It used UHF and SHF Line of sight radios (C50 as well as C 70), interconnected through Commcentres.  The heart of the voice system were Strowger terminal and tandem telephone exchanges.


Crypto Engine

Data Transfer Device (DTD)

LARKSPUR - Larkspur was a combat net radio operating at HF and VHF, with radios such as C11/R210 at HF and C42 at VHF and was replaced by Clansman: the frequency synthesis techniques used in Clansman revitalised the use of HF comms. A detailed description of the radios is available on the Wireless Warrior web page.


An encrypted telegraphic system providing secure telegraph over a civil or military bearer system.


Need info. Contact


PTARMIGAN - An area communications system which is the current one in use and it replaced  Bruin. It took 25 years to develop and was operational in 1985.


STEAMVALVE - The acronym means Secure Tactical Electronic Amplitude Modulated Voice Actuated Long-range Vestigial Emanations.  A shipboard HF secure voice system whose crypto component was a KG-13. No other info is available at this time.


1) Royal Signal Corps Museum

Back To Home Page

Feb 23/15