Figure 5-12.--A properly made-up sound-powered telephone headset-chestset.

LOADING HEADSET-CHESTSETS.-- Sound-

powered telephone headset-chestsets are designed to

operate with 10 sets in parallel without any noticeable

effect in response. However, it is possible to parallel up

to 20 sets before overall line level response is considered

critical. To maintain the overall efficiency of the circuit,

do not tape down the transmitter button for convenience,

as this may overload the circuit. When using the

headset-chestset, hold the press-to-talk switch down

firmly to ensure good contact, and talk directly into the

transmitter. When listening, be sure to release the

press-to-talk switch to eliminate the pickup of

extraneous sounds and also the loss in receiver signal

strength due to the low impedance transmitter shunted

across the line.

REMOVING HEADSET-CHESTSETS.-- When

removing a sound-powered telephone headset-chestset,

you should use the following proceedure:

1. Remove the headband and hang it over the yoke

of the transmitter.

2. Remove the plug from the jackbox and replace

the jack cover on the jackbox to keep out moisture and

dirt.

3. Lay the cord out on the deck and remove any

kinks.

Figure 5-12.--A properly made-up sound-powered telephone

4. Coil up the cord, starting from the end that

headset-chestset.

attaches to the chestplate. Coil with the right hand,

making the loops in a clockwise direction. The loops

should stow these sets in stowage boxes, which are

should be about 10 inches across.

designed for stowing one set or up to six sets.

5. After the cord is coiled, remove the headband

A properly made-up set should fit into its stowage

from the transmitter yoke and hold the headband in the

box without forcing. Never allow a loose cord to hang

same hand with the cord.

out of the box because it maybe damaged when the lid

6. Fold the transmitter yoke flat so that the

is closed. Never use the stowage box for storing cleaning

mouthpiece lays flush against the chestplate connection

gear or tools because rags give off moisture and soap

box, using care not to pinch the transmitter cord.

powder gives off fumes that will cause the aluminum

diaphragms to rapidly oxidize. Tools and other loose

7. Hold the headband and cord in the left hand and

gear may damage the set(s) or may prevent you from

unhook one end of the neck strap from the chestplate.

getting a set out quickly in an emergency situation.

8. Bring the top of the chestplate level with the

headband and cord. Secure the chestplate in this position

by winding the neck strap around the headband and

Sound-Powered Telephone Maintenance

coiled cord just enough times so that there will be a short

end left over. Twist this end once and refasten it to the

As an IC Electrician, you will be required to service

chestplate. The set is now made up and ready for

sound-powered telephones. Because a great deal of time

stowing, Figure 5-12 shows a properly made up

is devoted to the repair of these sets, you should become

sound-powered telephone headset-chestset.

thoroughly familiar with the proper methods of testing

STOWING HEADSET-CHESTSETS.-- In

and repairing them. Many of the larger ships in the fleet

have a telephone shop devoted entirely to the repair of

enclosed spaces, you should stow headset-chestsets on

sound-powered telephones.

hooks. In machinery spaces and on weather decks, you

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