c. Standby Reversionary Mode. The standby
(STBY) reversionary mode is generally used to
compensate for a failure of the pilot's or copilot's
symbol generator. Pressing the respective pilot's or
copilot's SG switch indicator, located on the instrument
panel, substitutes the MFD symbol generator for the
failed symbol generator. The lower half of the SG
switch illuminates STBY to indicate that the standby
reversionary mode has been selected.
3A-24. VHF NAVIGATION RECEIVERS (KNR 634A).
a. Introduction. Two VHF navigation receivers,
combining VOR, localizer, glideslope, and marker
functions, are installed. Each receiver provides 200
channels in the frequency range of 108.00 through
117.95 MHz (160 VOR channels and 40 localizer
channels). Selection of VOR or localizer is automatic.
Each receiver also provides 40 glideslope channels in
the frequency range of 329.15 to 335.00 MHz and a
marker receiver that operates at 75 MHz. The VHF
navigation receivers are powered through the 2-
ampere NAV NO. 1 and NO. 2 circuit breakers,
located on the right sidewall circuit breaker panel,
b. VHF Navigation Receiver Control Unit
(KFS 579A) Controls and Functions. The VHF
navigation receiver control unit controls the number
one VHF navigation receiver. The number two VHF
navigation receiver is controlled by the NAV/TAC
navigation receiver control unit. Refer to Figure 3A-19.
(1) Active Frequency Display. Displays the
active frequency (frequency to which the receiver is
automatically controls display brightness.
frequency transfer switch is a push-button switch that
transfers the frequency in the standby display to the
active display and the frequency in the active display
to the standby display.
1. Active Frequency Display
3. Frequency Transfer Switch
4. Megahertz Tuning Knob
5. Kilohertz Tuning Knob
6. Channel Switch
7. Power and Volume Control
8. Standby Frequency Display
Figure 3A-19. VHF Navigation Receiver Control Unit (KFS 579A)