4-47.3. LOUD HAILER- MAINTENANCE INSTRUCTIONS
(b) Description of controls. There are three controls on this equipment. The trigger switch
located in the front of the pistol-grip handle closes the battery supply circuit to the equipment. The toggle
switch in the base of the handle permits selection of either internal dry batteries (when operated to "INT") or
external battery supply (when operated to "EXT"). The volume control is operated by the knob located on the
rear housing directly under the microphone grille.
Sequence of operation. To operate the loud hailer effectively proceed as follows:
1 Internal or external power supply.
a Decide whether internal or external battery supply is to be used. For general use,
during which short, intermit- tent messages are delivered, the internal battery is satisfactory and most
convenient. When extended use and long messages are anticipated use an external battery.
b Operate the toggle switch to "INT" for use with internal battery.
c Operate the toggle switch to "EXT" for use with an external battery. Plug the external
battery cable into the receptacle in the handle and secure with the locking ring. Connect the battery clips
observing proper polarity to a 12 volt storage battery.
2 Use of loud hailer.
a Hold the loud hailer up to the mouth with the microphone as close as possible.
Actuate the trigger switch, with the first and second fingers of the hand that is grasping the handle. If the
system feeds back, back off the volume control until feedback stops. If, however, there is no feedback to start
with, as will occur if there are no reflecting surfaces, increase the volume setting as far as possible without
feedback starting. It is advisable to talk test (1, 2, 3, 4, etc.) while making these adjustments. Release the
trigger switch as soon as the adjustment is satisfactory.
b This switch is to be operated, only when it is necessary to transmit a message, and
should then be released immediately. This is particularly important when operating from the internal dry
battery, in order to obtain the maximum battery life.