TM 1-1520-218-10
3C-202
placarded MODE OFF / STBY / ON / FP / TEST,
which selects primary radar operating mode.
(a) OFF. Removes system power.
(b) STBY. Places system in non-
operational status.
(c) ON. Selects the WX or MAP
weather display.
(d) FP. Selects system flight plan
(navigation) display mode.
(e) TEST. Selects system self-test
mode.
(11) GAIN Control. The GAIN control is a
rotary control, which regulates receiver gain. A
detented PRESET position is provided at the full
clockwise end of rotation. Full counterclockwise
rotation sets minimum receiver gain. Full clockwise
rotation (not into the detent) commands minimum gain
of approximately 6 to 8 decibels higher than preset
gain.
c. Multifunction
Display
Radar
Graphics
Control Unit (MC-800). Refer to Figure 3C-148.
(1) MAP / PLAN Key. The MAP / PLAN key
selects either the MAP or PLAN display mode. In
MAP mode, radar Sensitivity Time Control (STC)
circuitry is disabled for ground mapping operations. In
PLAN mode, a NAV PLAN format is selected. This
mode is a north up mode in which the aircraft symbol
is positioned with respect to the NAV route and
progresses along the displayed route. Weather
information is not displayed while in PLAN mode.
(2) Weather
Key.
The
weather
key,
placarded WX, adds weather information to the
multifunction display.
1. MAP/PLAN Key
2. Weather (WX) Key
3. Cursor Joystick
4. Normal (NORM) Checklist Key
5. Emergency (EMER) Checklist Key
6. Skip (SKP) Key
7. Enter (ENT) Key
8. Recall (RCL) Key
9. Page (PAG) Key
10. Multifunction Display Brightness Control
11. Data (DAT) Key
12. VOR Key
13. Airport (APT) Key
14. Range Control
Figure 3C-148. Multifunction Display Graphics Control Unit (MC-800)
(3) Cursor Joystick. The cursor joystick
positions the cursor on the multifunction display screen
while in the MAP or PLAN mode. While the system is
displaying the normal or emergency checklists, vertical
