TM 1-1520-238-10
4-72
Table 4-23.
AN/APR-39(V)1 Radar Warning System (CRT) Control/Indicator Functions
Control/
Indicator
Position
Function
PWR
ON
Turns set on. Fully operational after 1-minute warmup.
OFF
Turns set off.
DSCRM
Selects mode of operation.
ON
Activates discriminator circuit.
OFF
Deactivates discriminator circuit.
SELF-TEST
When pressed, initiates self-test check (except for antenna and receiver).
AUDIO
Adjusts volume to the intercommunications system.
4.37.1 AN/APR-39(V)1 Operating Procedures.
The
procedure for turning on and off the RW equipment is as
follows:
CAUTION
To prevent damage to the receiver detec-
tor crystals, assure that the radar warn-
ing set antennas are at least 60 meters
from active ground radar antennas or 6
meters from active airborne radar anten-
nas. Allow an extra margin for new, un-
usual, or high power emitters.
1. Equipment on.
PWR switch – ON. Allow
1-minute for warm-up.
2. BRIL and filter controls – Adjust as desired.
3. AUDIO control – Adjust volume as desired.
4. DSCRM switch – Set for mission requirement.
5. Equipment off.
PWR switch – OFF.
4.37.2 AN/APR-39(V)1 Radar Warning Display Con-
trols.
The operating controls of the RW display, located
on the right side of the pilot instrument panel (fig 2-9 and
4-21), are described in table 4-24. The display shows a
line-of-bearing radial stroke for each processed signal.
Table 4-24.
AN/APR-39(V)1 Radar Warning Display Control/Indicator Functions
Control/Indicator
Function
BRIL Control
Adjust CRT display brightness.
MA Indicator
Missile Alert. Flashes on and off to indicate time correlation between missile guidance and
associated tracking radar.
Filter Control
Varies density of red polarized CRT faceplate filter (used for day or night operation) by
moving tang right or left.
