FUNCTIONVOR to localizer antenna transferoccurs after localizer capture and the NAV mode select switch is in ILS or LAND position
Enable the selection of either VOR/ILSreceiver 1 or 3 as the radio nav signalsource for the AP/FD system and thecaptain's flight instrument displays or selection of either VOR/ILS receiver 2 or 3 as the radio nav signal source for the AP/FD system and the first officer's flight instrument displays
Enables the captain to select eitherVOR/ILS receiver 1 or 3 as the radionav source for the AP/FD system andthe captain's flight instrument displays or either VOR/ILS receiver 2 or 3 as the radio nav signal source for the AP/FD system and the first officer's flight instrument displays
Enables the captain to select coursedeviation data from VOR/ILS receiver1, 2 or 3
Enables the first officer to selectcourse deviation data from VOR/ILSreceiver 1, 2 or 3Enables the pilots to select coursepresentation from either the VOR/ILSnavigation system or from the INS
EFFECTIVITY
AZ ALL
AT ALL
IB ALL CONFIG 2 SN ALL 02 Page 12 Apr 25/86
34-31-00
(7)
VOR/LOC antenna switch 1 Selects rf from either the VOR antenna or the lower localizer antenna for VOR/ILS receiver 1
(8)
VOR/LOC antenna switch 2 Selects rf from either the VOR antenna or the lower localizer antenna for VOR/ILS receiver 2
(9)
VOR/LOC antenna switch 3 Selects rf from either the VOR antenna or the upper localizer antenna for VOR/ILS receiver 3
(10)
VOR/LOC antenna switch 4 Switches rf from the VOR antenna to VOR/ILS receiver 1 or 3
(11)
VOR/LOC antenna switch 5 Switches rf from the VOR antenna to VOR/ILS receiver 2 or 3
13. ILS Buffer Amplifiers (AT ALL; AZ 221-299; SN 351-399; IB 406-499)
_____________________
A. On AT ALL, four ILS buffer amplifiers are installed in flight instrument relay panel P73.
B. On AZ 221-299; SN 351-399; and IB 406-499, two ILS buffer amplifiers are installed in flight instrument relay panel P73.
C. The amplifiers isolate the ILS deviation and flag warning outputs circuits of the auxiliary (3rd) VOR/ILS receiver from a fault in these circuits of the No. 1 or the No. 2 VOR/ILS navigation systems. If a fault occurs, and either the captain or the first officer select the 3rd receiver, the amplifiers prevent the fault from damaging the 3rd receiver or the ILS deviation and warning input circuits to channel C of the fail-operative AP/FD system.
14. Operation
_________
A. Functional Description, VOR/ILS Operation
(1)
The VOR/ILS navigation system provides VOR/LOC data via the VOR antenna when the AP/FD NAV mode select switch is placed in either the INS, HEADING or VOR/LOC position, the appropriate frequency is selected on the VHF NAV control panel, and 28 volts dc power is supplied to the VOR/ILS receiver.
(2)
The systems receive VOR/LOC signals in the frequency range of 108.00 to 117.95 MHz. This provides 160 VOR channels and 40 localizer channels with channel spacing of 50 kHz. Glide slope signals are in the frequency range of 329.15 to 335.00 MHz with 40 channels spaced at 150 kHz. Frequency selection is accomplished electronically using the two-out-of-five binary-coded-decimal system.
B. Functional Description, VOR/LOC Mode Operation (Fig. 2)
(1) COLLINS 51RV-2B Receiver
EFFECTIVITY
AZ ALL
AT ALL
IB ALL CONFIG 2 SN ALL 03 Page 13 Apr 25/86
34-31-00
(a)
Frequency select information from the control panel is converted to binary-coded-decimal data in the VHF synthesizer portion of the receiver. This data controls divider ratios in the synthesizer phase-locked loops. The synthesizer provides the required injection frequencies and tuning voltages for the first mixer in the VHF NAV receiver section. Navigation signals are selected by a tuned rf filter controlled by the tuning voltages from the VHF synthesizer. The signals are processed, gain stabilized, and fed to a detector (all in the receiver section), which provides receiver signals to the VOR and localizer instrumentation sections and drives an audio amplifier to provide an audio output to the flight interphone system (23-51-00).
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本文鏈接地址：747飛機維護手冊AMM CHAPTER 34 - NAVIGATION 第34章導航2(7)
