Figure 7-33.--AN/PIC-2 public address set.

3. Two-way intercommunication between selected

stations.

4. Alarm signals that may be broadcast over the

general announcing system.

5. An emergency reporting system providing for

the one-way communication of emergency

reports from any compartment in the submarine

to selected areas.

6. An escape trunk communication system that

may be interconnected to selected stations; that,

in an emergency, may be disconnected from the

ship communication system and operating on its

own auxiliary storage battery supply; and that

may be used for communication between the

escape trunk and adjacent compartments.

7. A system for use in the sonar control room that

Figure 7-33.--AN/PIC-2 public address set.

allows the sonar evaluator to break in on a sonar

operator for communication purposes.

the set to an external 12-volt battery when desired. The

8. A portable loudspeaker control unit that maybe

driver unit, microphone, amplifier enclosure, and

connected to the ship control unit extension

battery enclosure are watertight.

cable for use in communicating from the deck

To operate the set, put the battery selector switch to

watch to the control room when the ship is at

the INT. position (or to the EXT. position if operation is

anchor or in port. The portable unit may also be

to be from an external battery). Grasp the pistol-grip

used on the general amounting system.

handle with one hand, raise the unit so that the rubber

microphone is almost touching the mouth, and direct the

PUBLIC ADDRESS SETS

horn in the direction it is desired to communicate. Press

the press-to-talk switch and speak directly into the

Public address sets are used at fleet landings and in

microphone in a strong voice. Release the press-to-talk

amphibious operations to direct the movement of

switch when the message is completed. The set is

personnel, vehicles, and small boats; to communicate

specially designed to eliminate acoustic feedback to the

between ships and small boats; and to address personnel

extent possible. Acoustic feedback may occur, however,

aboard ship where high noise levels are present or where

if the horn is directed toward a reflecting surface, such

the installed announcing system is inoperative or

as a deck or bulkhead. When using the set below decks,

impractical. They are also used for entertainment and

back the volume control knob off until feedback stops,

such functions as church services, wardroom and ready

and then advance it gradually to a point where maximum

room briefings, change-of-command and other

volume without feedback is obtained.

ceremonies, and personnel training. The two types of

public address sets are the electronic megaphone type

and the portable amplifier or lectern type.

Amplifier Circuit

PUBLIC ADDRESS SET AN/PIC-2

The transistor amplifier is a three-stage,

transformer-coupled, push-pull type. It consists of

The AN/PIC-2 is an electronic megaphone-type

volume control R1, input transistor Q1, interstage

public address set designed to perform under extremes

coupling transformer T2, push-pull power transistors

of temperature and high humidity. The set consists of a

Q3 and Q4, and output inductor L1.

loudspeaker horn, a microphone, a transistor amplifier

assembly, a driver unit, eight D-size batteries, and a

DC Power Circuits

pistol-grip handle with a press-to-talk switch, battery

selector switch, and external battery connector. All

The 12-volt dc supply is selected from either the

components are housed in one assembly (fig. 7-33). A

internal or external batteries by battery selector switch

15-foot external power cable is provided for connecting

7-34