A tone disabler for bell system 1A echo suppressors
L. F. Bugbee · Transactions of the American Institute of Electrical Engineers Part I Communication and Electronics · 1962
The capability of simultaneous 2-way transmission over the direct distance dialing (DDD) network will allow data systems to provide more efficient error detection and correction, system control, and circuit assurance schemes. This capability is made available by the development of a tone disabler which will inhibit the suppression function of any echo suppressors in the connection upon command of a conditioning tone and allow normal operation on voice transmission. This paper describes the engineering design and operational features of the tone disabler.