Adf Tuning - BOMBARDIER LEARJET 40 Pilot's Manual

The memory functions and direct tuning operate the same as described
under COM operation, except the NAV window has an added function
called DME split tuning mode. Its operation is similar to the function
called DME hold. Depressing the DME function button on the RMU al-
lows the DME frequency to be tuned independent of the NAV frequen-
cy. Depressing the DME once causes the NAV window to split into two
sections, the top one being the active VOR frequency and the lower one,
now labeled DME, containing the active DME frequency in VHF for-
mat. In this condition, the DME may be tuned directly by simply press-
ing the line select key to place the cursor box around the frequency and
retuning using the tuning knobs. The DME digital station identifier will
appear adjacent to the DME nomenclature on the top edge of the DME
window. An amber H (hold) appears in the lower DME window. This
indicates that the distance display (DME or TACAN) is not paired with
the VOR/ILS navigation data. When the H is displayed on the RMU, it
will also be displayed following the DME read-out on the PFD.

ADF TUNING

ADF operation is the same as COM and NAV tuning in that depressing
the line select key beside the ADF frequency will place the cursor over
the frequency to be changed. Rotating the small tuning knob slowly
will advance the frequency in 0.5 kHz steps. This change will increase
to 10 kHz steps when the large knob is used. The RMU has the capacity
to store one ADF frequency in memory. This is done by selecting the de-
sired frequency, then depressing the STO function key at the bottom of
the RMU. To retrieve the stored frequency from memory, the frequency
line select key must be depressed for two seconds. ADF modes are also
controlled within the ADF window. Repetitively depressing the line se-
lect key adjacent to the ADF mode annunciator will step through the
available ADF modes of operation. This can also be accomplished by
placing the cursor over the mode annunciation, and using the tuning
knobs to step up or down through the available modes.
The ADF operating modes are as follows:
(1) ANT (Antenna) — ADF audio signal only.
(2) ADF — ADF receives signal and calculates the relative
bearing to the station.
(3) BFO (Beat Frequency Oscillator) — ADF adds a beat
frequency oscillator to detect continuous wave (CW)
signals.
(4) Voice — ADF has maximum audio clarity and fidelity,
but no bearing information.
PM-132A
Pilot's Manual
5-55