4-47.3. LOUD HAILER - MAINTENANCE INSTRUCTIONS (Continued).
(c) Pistol-grip handle assembly.
1 In addition to providing a means of holding the loud hailer at its center of balance, this handle
also incorporates the controls for the battery supplies. The handle, is provided with a cover,
held by three screws, trigger switch is normally open until actuated by the trigger. To apply
battery power to the amplifier, the two-position toggle switch selects either the circuit from the
internal battery, or from the external battery receptacle, the position being indicated on the
switch plate "INT" and "EXT" respectively. External battery power is furnished to the
receptacle thru the external battery cable, when the latter is connected to a 12 volt storage
battery, by means of the spring clips. The positive clip is marked with a plus sign, and is
insulated by a red rubber boot. The negative clip is insulated by a black rubber boot. It is
important that each clip be connected to the battery post of the same corresponding polarity,
as the amplifier will not operate with the polarity reversed. The battery posts should be clean
and the clips adjusted so as to bite into the metal and the posts.
2 The handle is provided with a "D" ring, which a carrying strap or a safety lanyard may be
fastened. The cap and chain assembly for the battery receptacle is secured under one of the
"D" ring mounting screws.
d. Preventative Maintenance.
(1) After long periods of storage, particularly at elevated temperatures, check the condition of
the dry cells and the contact springs in the battery holder. Inspect the microphone housing particularly. The
opening to the microphone should be kept free of dust, foreign matter, grease and oil and salt crystals. The
micro- phone grille cover should be removed occasionally and any such accumulated material as above should
be removed. The salt crystals left by the evaporation of salt water and spray should be dissolved with fresh
water and rinsed away after which the parts should be dried with a soft cloth or tissue.
(2) It is well to inspect the interior pistol-grip handle occasionally by removing the handle cover
to see that no salt or foreign matter has accumulated around the trigger or other parts in the interior. The power
receptacle should likewise be inspected and cleaned when necessary.
(3) After a time sand particles, cinders or the like may accumulate at the base of the horn. It is
advisable to invert the horn once in a while and shake out any foreign matter of this nature.