Wiretap-proof telephone (Jan, 1966)
This scrambler keeps private phone conversations safe from wiretappers and eavesdroppers. Fitted to an ordinary handset, it needs no electrical connection, has its own power source. To hear, a person needs an unscrambler coded identically. Delcon Division, Hewlett-Packard Co., Palo Alto, Calif., sells it for $275, keeps your name and code locked in its vault.