Thhs is an extract from the General Description page of the MA4014-B user manual.

The MA4014-B Encryption Unit provides a very flexible and secure means of encrypting and decrypting confidential information.

To achieve the necessary high level of speech or data security, the MA4014-B utilizes a time division scrambling technique in which information to be processed is split into small time segments which are rapidly shuffled into a new sequence. During operation, the shuffling codes are continually changing in a unique, pseudo random manner, approximately every half-second. The complexity and fast-changing nature of the encoded information is sufficient to prevent unauthorized receipt of intelligible signals even with the assistance of modern, computer-based codebreaking methods.

Over 600,000 internally selectable code keys are available, each of which is programmed by up to 64,000 codes selectable by front-panel switches. Thus over 4x10¹⁰ different programs are available.

The MA4014-B equipment is suitable for use with any radio H. F. or V. H. F. telephony communications equipment operating in any mode and is designed to change from 'clear' to 'private' operation automatically. This change occurs on receipt of a recognizable synchronizing signal from a remote station. Interface of the MA4014-B between data modems, teletype terminals and other special application data transmission systems can be provided together with a wide selection of cables and interconnecting systems.

The MA4014-B operates on-line within the voice bandwidth of any associated radio or field-telephone equipment, incorporates automatic signal levelling for synchronization purposes, and is substantially immune to the effects of channel noise, frequency drift and strong RF fields normally generated by nearby transmitters. No modification is required to the associated communication equipment.

Power consumption from the clip-on rechargeable battery is only 1 watt, giving approximately 28 hours of continuous operation. Automatic changeover to external supplies takes place if the battery voltage drops below a pre-determined value. Battery charging can be effected without removal of the battery from the main equipment and without breaking waterproof seals.

Above photos via E-bay

Oct 16/17