(4)  
The antenna TILT control provides manual control of the radar antenna elevation.

 (5)  
The GAIN control is used to adjust the gain of the receiver in the receiver/transmitter.

 3.  Receiver/Transmitter
____________________
 A.  The R/T units are installed in two single R/T mounts on the E5-1 and E5-2 shelf assemblies. The shelf assemblies are located on the centerline of the compartment floor in the nose cargo door section.
 B.  The R/T is a completely solid-state unit which transmits, receives, processes video, supplies antenna stabilization signals, and provides system timing and monitoring for the weather radar system. The R/T provides a nominal frequency of 9345-MHz transmission in the X-band frequency range for detection of weather conditions at ranges of up to 320 miles and for terrain mapping. A frequency agility feature shifts the frequency up and down from 9360 to 9330 MHz to reduce mutual interference with nearby transmitters. 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 R/T contains a microprocessor-controlled antenna stabilization servo loop, which provides antenna line-of-sight stabilization. Microprocessor-controlled system timing and monitoring of key system parameters for fault detection is also an integral part of the R/T function. See the R/T monitoring operations in the Receiver/Transmitter Functional Description.
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A

747-400
MAINTENANCE MANUAL

RECEIVER/ TRANSMITTER (2 LOCATIONS)
SEE A
FWD
RECEIVER/TRANSMITTER SEE BMOUNTS AND WAVEGUIDE
SWITCH - FREIGHTER
SEE C
WAVEGUIDE
FREIGHTER
PILOTS' OVERHEAD PANEL, P5
SEE L PILOTS' OVERHEAD
CAPTAIN'S  CIRCUIT BREAKER
WARNING SPEAKER  PANEL, P7
PILOTS' FIRST OFFICER'S
LIGHTSHIELD, P10 WARNING SPEAKER SEE K
FIRST OFFICER'S
CAPTAIN'S  MASTER WARNING
MASTER WARNING
AND CAUTION LIGHT AND CAUTION LIGHT
FIRST OFFICER'S
INSTRUMENT PANEL, P3CAPTAIN'S INSTRUMENT
PANEL, P1 SEED EF
SEEDI J
LEFT AND RIGHT WEATHER RADAR CONTROL DISPLAY CONTROL PANEL, P8 UNIT, P9
SEE G SEE H
FLIGHT COMPARTMENT
Weather Radar System - Component Location
Figure 1 (Sheet 1)

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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
M50252
A
747-400 MAINTENANCE MANUAL
BendixWX RADAR Air Transport Avionics
SYSTEM CHECKER RTA-4B SWXX VERXX
test menu
RECEIVER/TRANSMITTER  RIGHT RECEIVER/
TRANSMITTER A LEFT RECEIVER/
TRANSMITTER
SHELF ASSEMBLY (E5-2)
ANTENNA PLANAR ANTENNAARRAY DRIVE
ASSEMBLY
RECEIVER/ TRANSMITTER
FWD WAVEGUIDE MOUNT SWITCH
SHELF
ASSEMBLY
WAVEGUIDE TO E5-1
ANTENNA
RECEIVER/TRANSMITTER MOUNTS AND WAVEGUIDE SWITCH - FREIGHTER
C
TO RECEIVER/TRANSMITTER
WEATHER RADAR ANTENNA
B

Weather Radar System - Component Location
Figure 1 (Sheet 2)

M50264
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A

747-400
MAINTENANCE MANUAL

D

FIRST OFFICER'S DISPLAY TRANSFER MODULE

Weather Radar System - Component Location
Figure 1 (Sheet 3)

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