Vertex Standard VXA-150, Service Manual

Page: 15 / 32

15
Alignment
Alignment Point
PLL Reference Frequency
r
Connect the wattmeter, dummy load and frequency
counter connected to the antenna jack, and tune the
transceiver to 120.000 MHz.
r
Transmit, and adjust
TC1001
on the MAIN Unit, if nec-
essary, so the counter frequency is 120.000 MHz (±100
Hz).
TX Power Adjustment
r
Connect the wattmeter and dummy load to the anten-
na jack, and tune the transceiver to 128.000 MHz.
r
Transmit, and adjust
VR1003
to obtain 1.5 W RF (car-
rier) power indicated on the wattmeter (without au-
dio modulation input).
TX Modulation Adjustment
r
Connect the Radio Tester to the antenna jack, then ad-
just the AF generator output level for injection of 200
mV rms @ 1 kHz to the MIC jack. Leave the transceiver
tuned to 127.500 MHz.
r
Transmit, and adjust
VR1002
to obtain 85 % modula-
tion (±3 %) as indicated on the Radio Tester.
r
Reduce the AF generator output level to 20 mV rms,
then adjust
VR1001
to obtain 30 % modulation (±3 %)
on the Radio Tester.
Internal System Alignment Routine
This feature uses a programmed routine in the trans-
ceiver which replaces many previously-complex discrete
component settings and adjustments with digitally-con-
trolled settings via the
CHANNEL
selector knob. Trans-
ceiver adjustments include:
¦
Squelch Hysteresis Adjustment
¦
Squelch Threshold Adjustment
¦
Squelch “Tight” Adjustment
To begin, set the transceiver to 127.500 MHz, and turn
the transceiver off. Then, press and holding the
LAMP
switch,
PTT
switch and the
CHANNEL
selector knob while
turning the transceiver on.
Squelch Hysteresis Adjustment (HSSQ)
r
Press the
CHANNEL
selector knob, then select the
squelch hysteresis level using the
CHANNEL
selector
knob.
r
Next, press the
CHANNEL
selector knob.
r
Rotate the
CHANNEL
selector knob to select the next
setting.
Squelch Threshold Adjustment (THSQ)
r
Inject a –9 dBµ (0.35 µV) RF signal (with a standard
modulation: 30 % AM modulation @ 1 kHz), then press
the
CHANNEL
selector knob twice .
r
Now rotate the
CHANNEL
selector knob to select the
next setting.
Squelch “Tight” Adjustment (TISQ)
r
Increase the RF signal level to +15 dBµ (5.6 µV), then
press the
CHANNEL
selector knob twice .
r
Press and hold the in the
CHANNEL
selector knob for
2 second to save all setting and exit.
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 fac-
tory defaults),
press and holding the
MONITOR
button and
PTT
switch while turning the transceiver on.
TC1001
PLL Reference
VR1003
TX Power Adjustment
VR1002
TX Modulation Adjustment
VR1001
TX Modulation Adjustment
MADE IN JAPAN VERTEX STANDARD CO., LTD.
FCC ID:K66VXA-150
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