Figure 11-17.--Manua1 SB-22/PT telephone switchboard.
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.
SB-22/PT TELEPHONE SWITCHBOARD
The SB-22/PT telephone switchboard shown in
figure 11-17 is a lightweight, battery-operated, field
switchboard that has 12 interconnecting voice-
frequency circuits. The SB-22/PT is normally used to
interconnect local-battery telephone circuits,
remote-controlled radio circuits, and voice-frequency
teletypewriter circuits. Four BA-30 flashlight batteries
provide 3 volts of direct current for its operation. The
SB-22/PT has a range of 14 to 22 miles. The switchboard
Figure 11-18.--TA-221/PT operator's pack.
unit weighs about 30 pounds.
The SB-22/PT consists of four basic parts: the
The TA-1/PT can be used with the SB-22/PT
operator's pack (fig. 11-18); the line and trunk pack (fig.
telephone switchboard. To place an outgoing call with
11-19); the accessory kits (fig. 11-20); and the
the TA-1/PT, first press the generator lever. Then, listen
handset-headset (fig. 11-21).
for the distant party to answer. When you are ready to
Before operating the SB-22/PT switchboard, you
talk press the talk switch. When listening, release the
Dress-to-talk switch. The buzzer sounds for an incoming
should first become familiar with the different controls