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SUBMARINE ON BOARD COMMUNICATIONS
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Now, through
the intercom, Commander Alford tells his crew about his mission. Wherever they are on the
ship all the sailors can hear him. "At this point, I can feel the emotion of these
men echoing in me", he says. |
The general communications announcing system is comprised of
two voice communications circuits, one-way (1MC) and two-way (7MC). The same amplifier
equipment is used for both circuits. Generally, one channel is used for the 1MC and one
for the 7MC, but in an emergency both circuits may be operated through either of the two
individual amplifier channels.
An on-board sound powered telephone system which derives its
power from the sound of the voice. Vibrations from the voice cause a diaphragm to vibrate.
Attached to the diaphragm is a delicate needle, or armature, that is surrounded by a fine
wire coil held in place by a magnet. The movement of the armature inside the coil induces
current which is transmitted through the line to a receiver. The receiver is constructed
exactly like the transmitter. The current from the transmitted passes through the coil on
the receiver and causes the diaphragm to vibrate and reproduce the speaker's voice. The
system is divided into two circuits, the XJA (handset) used for routine ship's service
communication, and the JA (headset) used on all battle control stations.
The telephone call system consists of hand cranked signal
generators located in each compartment and require no supply voltage. Often referred to as
"growlers" each unit consists of a selector rotary switch used to select the
compartment desired and a small speaker that "growls" on the receiver unit to
notify the compartment of an incoming call. It is a separate complete circuit and is not
connected to the phone systems. |
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