changer, and pull it out on its slides until it locks in
(CCTV) is receiving wide use throughout the Navy.
So broad are the applications of television that a
special enlisted code is assigned to the IC Electricians
who maintain these systems.
located in drawers directly below the phonograph
record changer. The upper amplifier is used for
In comparing CCTV with commercial television,
channels 1 and 2, and the lower amplifier is used for
you will notice how nearly alike they are in operation.
channels 3 and 4. A power switch is located on the
The major difference is the methods of transmitting
front of each amplifier drawer.
the picture and sound. In CCTV, several methods of
transmission are used to bring the signals from the
camera to the receiver/monitor. These units may be
physically connected using telephone or coaxial
cables for short distances. For greater distances, or
When the ship's entertainment system is
when numerous receivers/monitors are involved,
operating, the following procedures should be
transmission is normally accomplished through the
same media as commercial transmission. This may be
accomplished by using a standard transmitter on
Never permit a program to peak into the red
specially assigned frequencies. When a receiver is
area of the volume output meter unnecessarily.
used, the receiver is generally a standard television
Monitor the output levels of all four channels
receiver. The monitor is basically the same as the
frequently. An increase could overload the am-
television receiver except that the set does not use a
plifier and cause damage. A decrease could be
tuner or associated circuits.
caused by a short circuit or an amplifier mal-
Monitor each program source routinely for dis-
To understand how a TV system works, you must
know what information is passed from the camera to
the receiver. There are four basic kinds of information
Never permit a tape to run out unexpectedly, a
needle to stick in a record groove, or distorted
sound to be broadcast.
Video signal--This signal is the actual moment-
to-moment information that tells the receiving set how
Keep tape recorder/reproducer tape heads and
light or dark each little spot in the picture should be.
Unlike movies, in which an entire picture is flashed
upon the screen every 1/24th of a second, TV pictures
Keep phonograph needle and stylus clean, and
are built up, line by line (525 horizontal lines per
play only clean unscratched records.
picture) and spot by spot within each line (approxi-
mately 426 spots per line). In TV, 30 complete pictures
are produced every second.
Blanking signals--These signals tell the camera
and the receiving set when no video signal should be
The type of loudspeaker used with the ship's
present (such as between the end of one line and the
entertainment system are the permanent-magnet,
beginning of the next).
direct-radiator type. Each loudspeaker contains a
volume control switch and a channel selector switch.
Sync signals--Sync (synchronizing) signals are
required to tell the receiving set exactly when to begin
each picture (vertical sync) and when to begin each line
within that picture (horizontal sync).
Audio signals--The audio is the sound, or
Television is a rapidly advancing area where IC
Electricians are used. Closed-circuit television
audible, portion of the total TV presentation.