Figure 5-7.--Wiring diagram of the H-203/U sound-powered telephone handset.

power is not required. The sound waves produced by the

transmitter's (talker's) voice is the only energy

necessary for the reproduction of the voice at the

receiver's telephone. The acoustic energy of the talker's

voice is converted into electrical energy in the

sound-powered telephone transmitter unit and

transmitted, via connecting wires, to the receiving

sound-powered telephone. The receiving sound-

powered telephone receiver unit reconverts the

electrical energy into acoustic energy. The types of

sound-powered telephones used in the sound-powered

system are the handset and the headset-chestset.

Sound-Powered Handsets

Sound-powered telephone handsets are designed

for general use on a line with other handsets or

headset-chestsets. Figure 5-6 is an illustration of a type

H-203/U sound-powered telephone handset and handset

holder. This type of handset has a nonkinking retractable

cord. Another type of handset is the H-203/U

(modified). This handset is identical to the type H-203/U

except that the handset cord is straight and contains no

less than two conductors in a single shield. The H-203/U

(modified) is modified to meet security requirements of

the ship's communication center.

Sound-powered handsets are hard-wired into

sound-powered jackboxes, selector switches, and

magneto call stations. For stowage of the handsets,

handset holders are installed in enclosed spaces, and

handset stowage cabinets are installed at stations

exposed to the weather.

Figure 5-6.--The H-203/U sound-powered telephone handset

Figure 5-7 is a wiring diagram of a type H-203/U

and handset holder.

sound-powered telephone handset. The nonlocking,

SOUND-POWERED TELEPHONE

normally open, spring return, push switch, S1,

HANDSETS AND HEADSET-CHESTSETS

disconnects the sound-powered transmitter and receiver

The sound-powered telephone system is

units from the line in the open position, and connects the

comparatively reliable because external electrical

units to the line in the closed (depressed) position.

Figure 5-7.--Wiring diagram of the H-203/U sound-powered telephone handset.

5-9