Vertex Standard VXA-300 Pilot III, Service Manual

Page: 14 / 32

14
Alignment
VOR Section
VOR Sensitivity Adjustment
Connect the Radio Tester to the antenna jack, then ad-
just the output level to +5 dBµV (with a standard AM
modulation: 30 % AM modulation @ 1 kHz) at 108.000
MHz.
Set the transceiver to 108.000 MHz and turn the trans-
ceiver off.
Press and hold in the PTT switch, MONITOR switch,
and VOLUME knob while turning the transceiver on
to enter the alignment mode.
Rotate the DIAL selector knob to select “
10 VSTR xxx
.”
Press the VOLUME knob twice.
Turn the transceiver off.
VOR Hysteresis Adjustment
Connect the Radio Tester to the antenna jack, then ad-
just the output level to +5 dBµV (with a standard AM
modulation: 30 % AM modulation @ 1 kHz) at 108.000
MHz.
Set the transceiver to 108.000 MHz and turn the trans-
ceiver off.
Press and hold in the PTT switch, MONITOR switch,
and VOLUME knob while turning the transceiver on
to enter the alignment mode.
Rotate the DIAL selector knob to select the “
11 VSHS
xxx
.”
Press the VOLUME knob momentarily, then adjust the
hysteresis level using the DIAL selector knob.
Press the VOLUME knob again.
Turn the transceiver off.
VOR Angle Adjustment
Connect the Avionics Radio Tester to the antenna jack.
Set the transceiver to 108.000 MHz, set up the “
FROM
”
mode (press [ F
] + [
3 ( FROM
)] key, if necessary), and
set the Avionics Radio Tester as shown below.
Frequency : 108.000 MHz
Output Level : +40 dBµV
30 Hz VAR. : 30 %
9.96 kHz Carrier : 30 %
9.96 kHz Modulation : 480 Hz
DIRECT : FROM
PHASE : 15 °
Note the difference of the phase indication between
the Transceiver ’s indication and Avionics Radio
Tester’s indication, then turn the transceiver off.
Press and hold in the PTT switch, MONITOR switch,
and VOLUME knob while turn the transceiver on to
enter the alignment mode.
Rotate the DIAL selector knob to select “
12 VOR xxx
.”
Press the VOLUME knob momentarily, then set the
difference value that is noted step 3 above, using the
DIAL selector knob.
Press the VOLUME knob twice
Turn the transceiver off.
Resetting the CPU
If you are unable to gain control of the transceiver (or if
you want to clear all memories and settings to their facto-
ry defaults), press and hold in the
MONITOR button and
VOLUME knob while turning the transceiver on.