TM 1-1520-240-10
4-1-3
Figure 4-1-1. Radar Signal Detecting Set Indicator
4-1-2. CONTROLS AND FUNCTION, RADAR SIGNAL
DETECTING SET INDICATOR
CONTROLS/
INDICATOR
FUNCTION
MA Lamps
Not used in the AN/
APR-39A(V)1 system.
BRIL Control
Sets indicator display
brightness. Turn clock-
wise to increase bright-
ness. Adjust for best
readable display of plus
(+) symbol.
MA Lamp Switch
Not used in the AN/
APR-39A(V)1 system.
CONTROLS/
INDICATOR
FUNCTION
Plus (+) Symbol
Displayed in the center of
indicator during operation
and self-test. Plus (+)
symbol flashes to let
operator know when the
system is operating in a
dense signal environment
and threat detection is
degraded.
Tick Marks
The
12
outer
edge
markings on the indicator
graticule, represent clock
positions
relative
to
aircraft heading.
Threat Symbol
Typical Threat
