*
FAIL LED-shows red after a test if there are failures
*
PUSH TO TEST switch -push this switch to start a test of the RFU.
EFFECTIVITY BEJ ALL 23-15-00
Page 26
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
SATCOM SYSTEM -RADIO FREQUENCY UNIT
EFFECTIVITY BEJ ALL 23-15-00
Page 27
D633W101-BEJ Jan 05/2002
SATCOM SYSTEM -ATTENUATOR
Purpose
The attenuator adjusts the radio frequency signal level to make the output from the RFU compatible to the input level needed for the HPA.
Physical Description
The attenuator has these properties:
*
Length -2 inches
*
Diameter -.5 inches
*
Weight -1.3 ounces.
EFFECTIVITY BEJ ALL 23-15-00
Page 28
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
SATCOM SYSTEM -ATTENUATOR
EFFECTIVITY BEJ ALL 23-15-00
Page 29
D633W101-BEJ May 05/2002
SATCOM SYSTEM -BEAM STEERING UNIT
Purpose
The beam steering unit (BSU) points the radio frequency signals at the satellite.
Physical Description
The BSU has these properties:
*
Length -14 inches
*
Width -10 inches
*
Height -4 inches
*
Weight -18 pounds.
EFFECTIVITY BEJ ALL 23-15-00
Page 30
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
SATCOM SYSTEM -BEAM STEERING UNIT
EFFECTIVITY BEJ ALL 23-15-00
Page 31
D633W101-BEJ Jan 05/2002
SATCOM SYSTEM -LOW NOISE AMPLIFIER/DIPLEXER
Purpose
The low noise amplifier/diplexer (LNA/DIP) is a filter and an amplifier. It lets the SATCOM system receive and transmit signals at the same time. It also increases the strength of received low level satellite signals.
Physical Description
The LAN/DIP has these properties:
*
Length -11 inches
*
Width -7.8 inches
*
Height -2 inches
*
Weight -6.6 pounds.
EFFECTIVITY BEJ ALL 23-15-00
Page 32
D633W101-BEJ Sep 05/2002
SATCOM SYSTEM -LOW NOISE AMPLIFIER/DIPLEXER
EFFECTIVITY BEJ ALL 23-15-00
Page 33
D633W101-BEJ Jan 05/2002
SATCOM SYSTEM -HIGH POWER AMPLIFIER
Purpose
The class A high power amplifier (HPA) increases the signal strength of transmit signals to the SATCOM antennas by as much as 40 watts for multiple channels or 80 watts for a single channel for a short time.
The class C HPA increases the signal strength by as much as 40 watts.
Physical Description
The class A HPA is an 8 MCU LRU and weighs 32 pounds. It has these front panel controls and indicators:
*
PASS LED -shows green after a test if there are no HPA failures
*
FAIL LED -shows red after a test if there are HPA failures
*
PUSH TO TEST switch -push this switch to start a test of the HPA.
The class C HPA is a 4 MCU LRU and weighs 15 pounds.
EFFECTIVITY BEJ ALL 23-15-00
Page 34
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
SATCOM SYSTEM -HIGH POWER AMPLIFIER
EFFECTIVITY BEJ ALL 23-15-00
Page 35
D633W101-BEJ Jan 05/2002
SATCOM SYSTEM -RADIO FREQUENCY COMBINER
Purpose
The radio frequency combiner (RFC) permits the SATCOM system to operate with more than one antenna. The RFC gets receive signals from the low noise amplifiers/diplexers (LNA/ DIPs). The RFC sends the received signal to the radio frequency unit (RFU).
Physical Description
The RFC has these properties:
*
Length -2.00 inches
*
Width -1.75 inches
*
Height -0.75 inches.
EFFECTIVITY BEJ ALL 23-15-00
Page 36
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
SATCOM SYSTEM -RADIO FREQUENCY COMBINER
EFFECTIVITY BEJ ALL 23-15-00
Page 37
D633W101-BEJ May 05/2002
SATCOM SYSTEM -RADIO FREQUENCY SPLITTER
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：777 AMM 飞机维护手册 通讯 Communications 1(19)
