A new single-channel carrier telephone system

ON OPEN-WIRE lines where the growth is not rapid, there is frequently need for adding telephone circuits one at a time. When the type-D single-channel carrier telephone system was developed a few years ago it became possible to meet this need without stringing additional wires.¹ More than 500 of these systems have been placed in service in the Bell System plant. A new single-channel carrier telephone system, known as the type H, has recently been developed and is now being applied. This new system offers improved performance, and also, because of its lower cost, is applicable to providing service over shorter distances than were economical with the earlier system.