Yaesu VX-120 Series, Technical Supplement

Page: 11 / 32

11
RF Front-end Tuning
1. Connect the DC voltmeter to TP1031 on the MAIN
unit, then inject a 145.050 MHz signal at a level of +10
dBµ (with 1 kHz modulation @±3.5 kHz deviation)
from the RF signal generator.
2. Tune the frequency to 145.050 MHz.
3. Press the [
F/W
] key, then press the [
MR
(
SKIP
)] key to
set the alignment parameter to “
A1 TUN.xxx
.”
4. With in five second of appearing the “
A1 TUN.xxx
” on
the display, adjust the DIAL knob so that the DC volt-
meter reaches maximum deflection. The VX-120/-170 ’s
RF Front-end has a broad bandwidth. Therefore, prior
to adjustment you must adjust the
DIAL knob to set
the frequency to the middle of the band, in step 2, so
you can set peak in the DC voltmeter’s deflection in
the center of the RF passband.
TX Power Output
1. Tune the frequency to 146.050 MHz, then set the trans-
mit power level to “LOW.”
2. Press the [ F/W
] key, then press the [
MR
(
SKIP
)] key to
set the alignment parameter to “
A2 PWR.xxx
.”
3. With in five second of appearing the “
A2 PWR.xxx
” on
the display, press the PTT switch to activate the trans-
mitter, adjust the DIAL knob so that the wattmeter read-
ing is 0.5 Watts (±0.05 Watt).
4. Increase the Transmit power level to “MID.”
5. Press the [
F/W
] key to recall the alignment parameter
“
A2 PWR.xxx
.”
6. With in five second of appearing the “
A2 PWR.xxx
” on
the display, press the PTT switch to activate the trans-
mitter, adjust the DIAL knob so that the wattmeter read-
ing is 2.0 Watts (±0.1 Watt).
7. Increase the Transmit power level to “HIGH.”
8. Press the [
F/W
] key to recall the alignment parameter
“
A2 PWR.xxx
."
9. With in five second of appearing the “
A2 PWR.xxx
” on
the display, press the PTT switch to activate the trans-
mitter, adjust the DIAL knob so that the wattmeter read-
ing is 5.0 Watts (±0.1 Watt).
TX Deviation
1. Tune the frequency to 146.050 MHz, then set the trans-
mit power level to “LOW.”
2. Press the [ F/W
] key, then press the [
MR
(
SKIP
)] key to
set the alignment parameter to “
A3 DEV.xxx
.”
3. With in five second of appearing the “
A3 DEV.xxx
” on
the display, press the PTT switch to activate the trans-
mitter, adjust the DIAL knob so that the deviation meter
reading is 4.2 kHz (±0.2 kHz) (EXP version: 4.5 kHz ±
0.2 kHz).
DCS TX Deviation
1. Tune the frequency to 146.050 MHz, then activate the
DCS, and set the transmit power level to “LOW.”
2. Press the [ F/W
] key, then press the [
MR
(
SKIP
)] key to
set the alignment parameter to “
A4 DCS.xxx
.”
3. With in five second of appearing the “
A4 DCS.xxx
” on
the display, press the PTT switch to activate the trans-
mitter (with no microphone input), adjust the DIAL
knob so that the deviation meter reading is 0.7 kHz
(±0.05 kHz).
Alignment
TP1031