Figure 2-7.AN/SAT 2 infrared transmitting set.
The IR transmitting set consists of two IR
transmitters (beacons), a transmitter control panel, and
two telegraph keys. The beacons may be operated
separately or simultaneously by either manual key.
Selection of the mode of operation is controlled by the
transmitter control panel. The IR transmitter consists
of a formed brass housing and a dome-shaped
homogeneous tempered glass filter, which encloses a
300-watt, 110-volt, T20 clear bulb incandescent lamp
and reflector. The transmitter control consists of a
watertight brass housing with a removable front cover,
and contains a switch, four fuses, two indicator lights,
two terminal boards, and associated wiring. The front
panel has a gasket to ensure a watertight fit, and is
fastened to the housing by means of eight machine
screws. Two locating pins ensure proper alignment of
the door and housing. (This control panel is also
utilized by the yardarm blinkers; however, this blinker
is powered by a separate ship's power supply to ensure
the circuit is inoperable during darken ship.) The
telegraph key consists of a watertight brass box
containing a signaling key, a monitor indicator light,
a terminal board, and a capacitor. The watertight
housing consists of a formed and welded steel box
with a formed steel cover and key guard. The cover is
attached to the housing by means of six machine
screws. A locating pin ensures proper alignment. The
base of the housing has three mounting lugs. The
hinged key guard on the cover protects the key from
damage when it is not in use. A hold-down lever
permits steady operation of the beacons when placed
in the down position.
Due to the constant exposure to the elements, strict
compliance with planned maintenance system (PMS)
requirements is essential for this equipment.
Normally, maintenance is the responsibility of the
Electrician's Mates. Cleanliness and upkeep of the
light exteriors are tasks for Signalmen. This upkeep
can be hazardous. Before going aloft, check Man Aloft
Procedures covered later in this chapter.
The most widely used IR transmitting equipment
is the standard 12-inch searchlight fitted with a type-H
hood containing the special filter lens (fig. 2-8). The
lens resembles a sheet of red glass. The light is
operated in the same procedure for regular directional
communication, but train must be more accurate.