Switchboard SB-5/PT is a 6-line, portable, magneto-telephone switchboard for use primarily in field wire systems. It weighs only 12 pounds and for that reason is especially valuable for jungle and mountain operations. This switchboard is similar to the BD-9 and BD-11 in that it has an operator's cord in addition to the line and trunk circuit cords, it has no talk-listen or ring keys, and it has no operator's telephone. A Telephone EE-8 may be used as the operator's telephone, and the magneto of this telephone will be used for ringing. The operator's cord is terminated in a red plug to distinguish it from the line and trunk cords, which have black plugs. Switchboard SB-5/PT differs from the BD-9 and BD-1 1 in that each line and trunk circuit includes both a ring jack and a talk jack, instead of one common jack. Operation of the SB-5/PT, which is comparable to operation of the BD-9 and BD-11 is explained fully in TM 11-2016.
- Switchboard SB-5/PT
- 25 April 1944