e. Battery installation. If you are going to use an external battery, be sure to check the battery
compartment and remove any batteries that are in it. Connect a 3-volt battery source to the BAT binding
posts on the panel. If you are going to use internal batteries, open the battery compartment by turning
the battery compartment latch clockwise. Insert one battery with the positive terminal up and one
battery with the positive terminal down. Close the compartment and turn the latch counterclockwise to
lock the cover closed (See Figure 1-2.)
Deicing screen. In cold climates, install the deicing screen to prevent the operator's breath from
finger or the blade of a screwdriver to press evenly around the rim of the screen and seat it firmly in the
slot around the face of the transmitter cap. To remove the deicing screen when not needed, insert the
blade of a screwdriver in the slot in the transmitter cap. Pry up the screen with a twisting motion. Store
the screen in the carrying case between the case and the side of the housing opposite the buzzer.
Installation of the off-hook lamp assembly. (See Table 1-1 for controls and indicators and their
NOTES: The security lamp is to alert personnel that handset H-60/PT is not seated
properly in its retaining brackets leaving the line open. The lamp is for use only in
sensitive areas; it is not to be installed on every telephone set in the field.
Remove the panel screw nearest the LINE binding posts. Secure the off-hook lamp
assembly to the panel with this screw, keeping the lamp portion of the attachment
snuggled near the telephone cradle. Run the lead of the off-hook lamp assembly around
the handset retaining bracket and connect its two terminals to the BAT binding posts on
Buzzer BZ-23/PT adjustment. Contact a distant party or the switchboard and ask them to ring on
the line. Adjust the LOUD-LOW control to the desired volume. The fully clockwise position of the
control is the maximum LOUD position.
10. Connecting handset-headset H-144( )/U. Connect handset-headset H-144( )/U by connecting the
plug on the H-144( )/U to the connector receptacle U-79/U on the panel of the TA-312/PT. Leave the
H-60/PT in the retaining cradle while the H-144( )/U is connected.
11. Initiating a call (CB and CBS operation using H-60/PT). Place the INT-EXT switch to INT.
Remove the H-60/PT from its retaining cradle and wait for the switchboard operator to answer. For
CBS operation, press the PRESS-TO-TALK switch to TALK and release it when listening. For CB
operation, do not use the PRESS-TO-TALK switch. When the call is terminated, replace the H-60/PT in
its retaining cradle.