Mk 123

This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. Please help improve this article by introducing more precise citations. (October 2026) (Learn how and when to remove this message)

The Mk. 123 (Mark 123) is a British compact, valve-based clandestine radio transceiver/transmitter-receiver set designed during the Cold War as a post-WW2 replacement for older radio sets like the Type 3 Mk. II (B2).

Usage

During the turmoil of the Iranian Revolution (including the period surrounding the seizure of the US Embassy and local communication cutoffs), a British Embassy technician used an off-site hidden Mk.123 transceiver to transmit emergency One-time pad (OTP) Morse code messages out of the country such as to relay points in Australia or Darwin.

References

External links

• Original Manual, Mk. 123 Transmitter/Receiver Technical Publication No. 82. Declassified 1996.
• Wireless Equipment, Mk 123 Transceiver, British
• Mk. 123 Transceiver England year 1956 - 57
• Cold War Clandestine Equipment