Sep 25/94

OFFSET DISPLAY SWITCHES
MARKER
INTENSITY
CONTROL

DISPLAY INTENSITY CONTROL
DISPLAY SELECT

RANGE SWITCHES SWITCHES

INDICATOR POWER SWITCH
INDICATOR E

OFFSET DISPLAY SWITCHES
DISPLAY SELECT SWITCH

RANGE SWITCHES

INDICATOR AF 160,162-171
AF 183,184

Weather Radar System Component Location Figure 1 (Sheet 4)

EFFECTIVITY
 CONFIG 4 AF 160,162-171,183,184
799 Page 5
34-43-00

Sep 25/94
MODE SELECT GAIN CONTROL SWITCH TILT CONTROL

GAIN CONTROL
TILT CONTROL

TRANSFER SWITCH

AF 160,162-171
AF 183,184
Weather Radar System Component Location Figure 1 (Sheet 5)

E39717
EFFECTIVITY

CONFIG 4799 Page 6AF 160,162-171,183,184
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Sep 25/94
 2.  Control Panel
_____________
 A.  The weather radar control panel is located on aft electronics control panel P8.
 B.  AF 160, 162-171; The control panel has a system transfer (SYS) toggle switch, a rotary mode select switch, a rotary antenna TILT control, a rotary receiver GAIN control and a two-position ground suppression toggle switch.
 (1)  
The system transfer switch allows selection of the left or right system also controls primary power to the selected system.

 (2)  
The rotary mode selector switch allows selection of TEST, WX, WX+T and MAP modes of operation.

 C.  AF 183, 184; The control panel has a rotary system transfer (SYS) switch, pushbutton mode selector switches, a rotary antenna TILT control, a rotary receiver GAIN control and a two-position ground suppression toggle switch.
 (1)  
The antenna TILT control provides manual control of the radar antenna elevation.

 (2)  
The GAIN control is used to adjust the gain of the receiver in the receiver/transmitter.

 (3)  
The ground clutter suppression switch or ground suppression switch is used to reduce the intensity of the ground clutter returns on the indicators.

 3.  Indicator
_________
 A.  Two weather radar indicators are installed. One indicator is on the captain's auxiliary side panel P44 and the other on the first officer's auxiliary side panel P45.
 B.  The weather radar indicator is a color indicator that provides a constant, nonfading display of all detectable targets within the scan angle and range selected. The indicator can display weather, turbulence, or ground maps. The display is generated from the information contained in a 1600-bit serial word, provided by the receiver/transmitter.
 C.  The indicator contains ARINC 453 interface receivers, video digitizer, level conversion, and second video amplifier circuits, a CRT with its associated high voltage power supply, range mark, electromagnetic deflection, front panel controls and sweep circuits. It is self-contained except for dc control signals from the control panel.
 D.  AF 160, 162-171; PWR pushbutton turns on the power to the selected R/T and the indicator.
 E.  INT (intensity) control varies the intensity of the video on the display.
 F.  MKR (marker) control varies the intensity of the range and azimuth marks.
 G.  Range switches select the nautical miles of the weather display on the indicator.
 H.  M/S pushbutton switch causes that indicator to display the same picture as the other indicator.
 I.  AF 160, 162-171; AZ pushbutton switch removes the azimuth liner from the indicator display.
 J.  AF 160, 162-171; HOLD pushbutton switch freezes the indicator display and prevents weather radar return updating.
 K.  The indicator pushbutton offset display switches are LFT, FWD and RGT.
 EFFECTIVITY

 AF 160, 162-171, 183, 184  CONFIG 4  01 Page 7  Sep 25/9434-43-00
115V AC

RADIO BUS
F/O NO. 2
INDICATOR

ESS RADIO BUS

DATA BUS 2 CONTROL

BUS 1

Weather Radar System Block Diagram
Figure 2

EFFECTIVITY CONFIG 4 AF 160,162-171,183,184
799 Page 8
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Sep 25/94
 (1)
LFT shifts the display to allow full range view to the left.

 (2)
FWD shifts the display for a centered view.

 (3)
RGT shifts the display to all full range view to the right.

 4.  Receiver/Transmitter
____________________
 A.  The R/T is a completely solid state unit which transmits, receives, processes video, supplies antenna stabilization signals, and provides system monitoring for the weather radar system. The R/T provides pulse transmission in the X-band frequency range for detection of storm conditions at ranges of up to 240 or 320 miles and for terrain mapping. The R/T contains circuitry which automatically compensates for near and far targets and weakened radar returns due to penetration of weather storm cells. The receiver/transmitter (R/T) contains the receiver, modulator, TR limiter, duplexer, stabilization, DC power supply, and control circuits. Peak power output from the crystal oscillator is approximately 125 watts at a frequency of 9375 MHz in the X-band. Pulse width is variable from 1 to 20 microseconds.
　
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