Transmission Features of the New Telephone Sets*

Abstract

The new telephone instruments now being introduced by the Bell System result in an outstanding improvement in transmission performance in service. The evidence for this, as obtained by comprehensive laboratory and field tests, is presented here together with a discussion of the factors responsible for this superior performance and of the consideration involved in its appraisal.

An Improved Circuit for the Telephone Set

“…4 To avoid this loss and make the higher efficiency provided by the new transmitter and receiver effective, a reduction in sidetone must be made. When the room noise level at the station is high, another undesirable effect of high sidetone occurs.…”