Table 3C-5. IND-42 Diagnostics
IDENT word missing
3C-24. AUTOMATIC DIRECTION FINDER (ADF).
a. Description. The ADF-60 system 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 1749.5 kHz. The ADF-60 system has three
functional modes of operation. In 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
HSI, and an aural output of the received signal is
provided. A TONE mode provides a 1000-Hz aural
output tone, when a signal is being received, to identify
keyed CW signals.
b. Operating Controls and Functions. All
operating controls for the ADF-60 system are located
on the CTL-62 ADF Control. Refer to Figure 3C-19.
(1) Compare Annunciator. ACT momentarily
illuminates when frequencies are being changed. ACT
flashes if the actual radio frequency is not identical to
the frequency shown in the active frequency display.
(2) XFR / MEM Switch. This switch is a
3-position, spring-loaded toggle switch. When held to
the XFR position, the preset frequency is transferred
up to the active display and the ADF-60 retunes. The
previously active frequency becomes the new preset
frequency and is displayed in the lower window. When
this switch is held to the MEM position, one of the four
stacked memory frequencies is loaded into the preset
display. Successive pushes cycle the four memory
frequencies through the display (
2, 3, 4, 1, 2, 3
(3) Frequency Select Knob. Two concentric
knobs control the preset or active frequency displays.
The larger knob changes the 1000's and 100's kHz
digits. The smaller knob changes the 10's, units, and
tenths kHz digits. Each detent of the larger knob
changes the frequency in 100-kHz steps. Each detent
of the smaller knob change the frequency in 1-kHz
steps with the exception that the first two detent
positions following a change in rotational direction will
cause a 0.5-kHz change. Rapid rotation of the smaller
knob will cause frequency changes greater than 1 kHz
as a function of the rate of rotation. Frequencies roll
over at the upper and lower limits. The two frequency
select switches are independent of each other such
that the upper and lower limit rollover of the 10-kHz
digit will not cause the 100-kHz digit to change.
(4) ACT Button. Push the ACT button for
approximately 2 seconds to enable the frequency
select knobs to directly retune the ADF-60. The
bottom window will display dashes and the upper
window will continue to display the active frequency.
Push the ACT button a second time to return the
control to the normal 2-display mode.
(5) TEST Button. Press the TEST button to
initiate the radio self-test routine. (Self-test is active
only when the TEST button is pressed.)
(6) Light Sensor. The built-in light sensor
automatically controls the display brightness.