Lesson 1/Learning Event 2
The MODE switch is a three-position switch which will place the TA-
312/PT into the correct network configuration depending upon signaling
and transmission power.
a. Common battery (CB)
supplied by a switchboard.
b. Local battery (LB) -Voice transmission power supplied by the
telephone (two BA-30 batteries); signaling power is supplied by hand-
c. Common battery signaling (CBS) -Signaling power supplied by the
switchboard; voice transmission power by the telephone (BA-30s).
Learning Event 2:
The TA-312/PT may be used as a desk phone or may be mounted
vertically on a tree, pole, or other support.
The first step in repairing the TA-312/PT is to verify the trouble
making a visual inspection as you complete these actions.
problems include terminal connections, batteries, and MODE switch