5. Briefly press WX/C push button and
slide TGT ALERT control to ON.
Verify that the letter T in a red box
appears in the target alert field.
6. Press TEST push button and observe
that when the test pattern display
crosses the centerline, the T is
replaced by a flashing TGT label.
Slide TGT ALERT control to OFF to
disable the function.
7. Verify that 100 (nm) is displayed in the
upper right-hand corner and that the
first four range marks are labeled with
the correct numerics.
8. Slide AZ MK control to ON and verify
that azimuth marks are displayed in
cyan at 30 intervals. Slide AZ MK
control to OFF to remove azimuth
9. Briefly press WX/C push button to
erase display, press TEST
2 seconds, momentarily press FRZ
and verify that the 1 2 3 display
beneath the color bar is replaced by a
flashing FRZ label. Verify that only a
portion of the test pattern is displayed
and there is no further updating.
Momentarily press FRZ push button
and verify that the display begins
updating starting at the current scan
10. Press 10 (nm) range push button and
restored to the previous display.
11. Briefly press WX/C push button and
verify that WX displays in the Mode
field and 10 displays as the selected
range. Verify correct range numerics.
12. Press each range push button in
succession (25 / 50/ 100 / 200 / 300)
and verify that range numerics change
appropriately with each selection.
13. Briefly press WX/C push button and
verify that CYC is displayed in the
GAI N control just out of
PRESET and verily that 1 2 3 remains
in the auxiliary field.
15. Briefly press WX/C push button and
verify that WX is displayed in the
mode field and that VAR replaces 1 2
3 in auxiliary field.
16. Briefly press MAP push button and
verify that MAP is displayed in the
Mode field. Verify that the color of the
range marks and alphanumerics is
17. Briefly press STBY push button to
return radar to non-transmitting state.
Return GAIN control to PRESET.
(4) Fault Displays. Display colors are
continuously monitored by the color bar and 1 2 3
legend in the auxiliary field. If a fault causes a change
to unfamiliar colors, the severity level denoted by the
faulty color(s) is directly coded by the 1 2 3 legend.
If the fault was of transient nature, the
system may operate satisfactorily.
Other circuits continuously monitor performance
and loading of system power supplies. A fault
resulting in power supply operation outside of preset
limits will cause the system to shut down and the
display will be blank. Should this occur, use the
following procedure to recycle the system:
1. Rotate INT / OFF control to OFF.
2. Verify aircraft radar circuit breaker is
3. After a few seconds, rotate INT / OFF
control to midpoint and press TEST
(5) Ground Mapping. Ground mapping
operation is selected by pressing the MAP push
button. Turn the TILT control down until the desired
amount of terrain is displayed. The degree of down tilt
will depend upon the type of terrain, aircraft altitude,
and selected range.
For the low ranges (10, 25, and 50), the
transmitter pulse width is narrowed and the receiver
bandwidth is widened to enhance the identification of