(5) TACAN Units Digits, NAV Kilohertz, and
TACAN X Or Y Tuning Knob. The TACAN units digits,
NAV kilohertz, and TACAN X or Y tuning knob is the
larger of the two knobs that are used to set the NAV
frequency or TACAN channel in the standby frequency
display. Rotation of this knob sets the three digits to
the left of the decimal point in the standby frequency
display or the 10's and 100's digits of a TACAN
channel depending on the selected mode. The
numbers will roll over at the upper and lower frequency
or channel limits.
(6) Channel Switch. The channel switch,
placarded CHAN, is a push-button switch, which is
used to select whether TACAN channel or frequency is
used in the active frequency or channel display.
(7) Power and Volume Control. The power
and volume control placarded OFF / VOL, controls
operation of the receiver control unit. Clockwise
rotation from the OFF position applies power to the
system and continued clockwise rotation increases
(8) Standby Frequency Display. Displays the
standby (inactive) frequency or channel.
c. Operating Procedures.
(1) Equipment Turn-On. The receiver and
the control unit are turned on by clockwise rotation of
the power and volume knob.
(2) Frequency Selection.
(a) Standby Frequency
When the receiver control unit is in the standby
frequency or channel entry mode, the active frequency
or channel, in the active frequency or channel display,
is selected by changing the frequency or channel in
the standby frequency display. Then transfer the
selected frequency or channel to the active display by
pressing the transfer switch. The frequency or
channel in the standby frequency or channel display is
changed by means of the tuning knobs on the control
unit. The control unit will remain tuned to the
frequency or channel in the active display as long as
the control unit is in the standby entry mode.
(b) Active Frequency Entry Mode. When
the receiver control unit is in the active frequency or
channel entry mode, the active frequency or channel
(in the active frequency or channel display) is changed
directly by rotating the tuning knobs. The receiver
control unit is changed to the active frequency or
channel selection mode by holding the transfer switch
pressed for longer than 2 seconds. Momentarily
pressing the transfer switch will change the receiver
control unit back to the standby entry mode and will
return the standby frequency or channel display to the
frequency or channel displayed before entering the
3A-26. AUTOMATIC DIRECTION FINDER (ADF)
RECEIVER (KDF 806).
a. Description. The ADF receiver provides
aural reception of signals from a selected ground
station and indicates relative bearing to that station.
The ground station must be within the frequency range
of 190 to 1750 kHz. In the ANT mode, the ADF
receiver functions as an aural receiver, providing only
an aural output of the received signal. In ADF mode, it
functions as an automatic direction finder receiver in
which relative bearing to the station is presented on an
associated bearing indicator, and an aural output of
the received signal is provided. The ADF receiver is
placarded ADF, located on the right sidewall circuit
breaker panel, Figure 2-6.
b. ADF Control Unit Operating Controls,
Indicators, and Functions. Refer to Figure 3A-21.
(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 each time it is pressed.
Pressing the frequency transfer switch for more
than 2 seconds while in the standby entry mode will
switch the receiver control unit to the active entry
Momentarily pressing the frequency transfer
switch while in the active entry mode will return the
receiver control unit to the standby entry mode.
(4) Kilohertz (100's) Tuning Knob. The
kilohertz 100's tuning knob is the larger of two
concentric knobs, which are used to set the frequency
in the standby frequency display. Rotation of the
larger tuning knob sets the 100's kilohertz digits in the
standby frequency display. The numbers will roll over
at the upper and lower frequency limits. Rotating the
kilohertz 100's tuning knob in either direction with the
receiver control unit in the channel mode will change
the channel number and its corresponding frequency.