Test Setup - Yaesu VX-7R - TECHNICAL Service Manual

Alignment

Test Setup

Set up the test equipment as shown below for transceiv-
er alignment, and apply 8.7 V DC power to the transceiv-
er. Refer to the drawings for Alignment Points.
Internal System Alignment Routine
This uses a programmed routine in the transceiver
which simplifies many previously complex discrete com-
ponent settings and adjustments with digitally-controlled
settings via front panel buttons and LCD indications.
To begin, set the transceiver to the center of the 50 MHz,
144 MHz, 222 MHz and 430 MHz bands. Next, select the
430 MHz band, then turn the transceiver off.
Now, press and hold in the MON/F,
(at the same time) while powering the radio on again.
The display will show the first setting. Thereafter, the
frequencies used during alignment will automatically be
set without action by the technician.
In the alignment process, each adjustment is selected
by rotating the DIAL. Alignment is performed by:
Pressing the V/M button;
m
Injecting a signal of the required frequency and lev-
m
el; then
Pressing the V/M button after a level setting or ad-
m
justment is made. This second pressing of the MON/
F button stores the entry.
To exit the alignment routine, press the HM/RV but-
ton. After performing the system alignment in its entire-
ty, individual settings can be returned to and adjusted
should the need arise.
As each transceiver is individually optimized at the
factory, the precise settings for the transceiver on your
bench may be slightly different.
Main Band Alignment
PLL Reference Frequency (PLL REF)
Press the V/M button, then transmit and adjust the
counter frequency to 440.000 (±300 Hz) by rotating the
DIAL, then press the V/M button. Rotate the DIAL to se-
lect the next setting.
430 MHz band Alignment
Squelch Hysteresis Adjustment (HIS SQL)
Rotate the DIAL for minimum squelch hysteresis. Press
m
the V/M button, then rotate the DIAL to select the next
setting.
12
Squelch Preset Threshold (THLD SQL) [86]
Inject a –15.0 dBµ RF signal (1 kHz tone @ ±3.5 kHz
m
deviation), then press the V/M button, then press the
MON/F button twice. Press the V/M button, then rotate
the DIAL to select the next setting.
Squelch Preset Tight (TIGH SQL)
Adjust the generator level to –4.0 dBµ, then press the
m
V/M button, then press the MON/F button twice. Press
the V/M button, then rotate the DIAL to select the next
setting.
S-Meter S-1 Adjustment (S1 LEVEL)
Adjust the generator level to –7.0 dBµ (1 kHz tone @
m
±3.5 kHz deviation), then press the V/M button, then
and 0 buttons
press the MON/F button twice. Press the V/M button,
then rotate the DIAL to select the next setting.
S-Meter Full-Scale Adjustment (S9 LEVEL)
Adjust the generator level to +20 dBµ (1 kHz tone @
m
±3.5 kHz deviation), then press the V/M button, then
press the MON/F button twice. Press the V/M button,
then rotate the DIAL to select the next setting.
Wide-FM S-Meter S-1 Adjustment (S1 LEVEL)
Adjust the generator level to 0 dBµ (1 kHz tone @ ±20
m
kHz deviation), then press the V/M button, then press
the MON/F button twice. Press the V/M button, then
rotate the DIAL to select the next setting.
Wide-FM S-Meter Full-Scale Adjustment (S9 LEVEL)
Adjust the generator level to +20 dBµ (1 kHz tone @
m
±20 kHz deviation), then press the V/M button, then
press the MON/F button twice. Press the V/M button,
then rotate the DIAL to select the next setting.
The alignment frequency will now be automatically set
to 430.000 MHz.
High TX Power Adjustment (HI POWER)
Transmit, and adjust the output power level for 5.0 W
m
(±0.3 W) by rotating the DIAL, then press the V/M but-
ton. Rotate the DIAL to select the next setting.
L3 Tx Power Adjustment (L3 POWER)
Transmit, and adjust the output power level for 2.5 W
m
(±0.2 W) by rotating the DIAL, then press the V/M but-
ton. Rotate the DIAL to select the next setting.
L2 Tx Power Adjustment (L2 POWER)
Transmit, and adjust the output power level for 1.0 W
m
(±0.1 W) by rotating the DIAL, then press the V/M but-
ton. Rotate the DIAL to select the next setting.