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Telephone No. 710
Used as Privacy Set voice terminal - this page is a stub

In the late 1950s, the GPO made the Frequency Changer — meanwhile renamed Privacy Set — to commercial parties. British manufacturer TMC, for example, marketed the equipment under the name Secraphone from the late 1950s to the late 1970s. Others kept using the name Privacy Set.

Privacy Set No. 7, 8 and 9 could all be used with the existing SA5030 voice terminal, but from approx. 1962 onwards, Telephone No. 710 and No. 740 were used as modern a replacement.

The introduction of the 710 and 740 telephone sets more or less coincided with the arrival of Privacy Set 8 and the replacement of manually switched and Local Battery (LB) systems.

For use with a Privacy Set, the No. 710 or 740 telephone set had to be modified. Like with the earlier SA503x terminals, the push-buttons at the top were configured for switching between clear and scrambled speech.

The image on the right shows a genuine No. 740 that turned with a Privacy Set No. 8 up in June 2013 at Gildings Auctioneers in the UK.

Telephone No. 710. Copyright Gildings Auctioneers [10].

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Crypto Museum. Created: Wednesday 26 May 2021. Last changed: Tuesday, 10 August 2021 - 16:35 CET.
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