The TA-1/PT telephone set is a lightweight, waterproof, sound-powered, field telephone for use on field-wire lines to communicate with other field telephones or local, battery-operated switchboards. The TA-1/PT is equipped with a visual, incoming-signal indicator and a generator ringer. It has a talking range of 3 to 6 miles, which is ideal for use on a listening post. The set weighs about 2.7 pounds. The basic parts of the set are shown in figure 11-16.

Figure 11-17.-Manua1 SB-22/PT telephone switchboard.

Figure 11-18.-TA-221/PT operator's pack.

The TA-1/PT can be used with the SB-22/PT telephone switchboard. To place an outgoing call with the TA-1/PT, first press the generator lever. Then, listen for the distant party to answer. When you are ready to talk press the talk switch. When listening, release the Dress-to-talk switch. The buzzer sounds for an incoming

Figure 11-19.-TA-222/PT line and trunk pack.

call except when the buzzer volume control is set in the OFF position. The visual indicator shows four white, luminous markings that remain visible until you press the talk switch. Rotate the buzzer volume knob to adjust the buzzer volume. For maximum volume, rotate the knob counterclockwise as far as possible. For volume less than maximum, first request the distant party or switchboard for a ringing signal. When the buzzer sounds, rotate the buzzer volume knob clockwise until you obtain the desired volume.