Overview Of Test Mode; Starting Test Mode - Standard Horizon Quest GX1255S Service Manual

Alignment

Overview of Test Mode

The test mode has been build in the microprocessor in or-
der to adjust and comfirm the performance of transceiver.
The purpose is to adjust transceiver simply and to con-
firm the performance of transceiver smoothly.
(a) Expansion channels "EXP01 - EXP06" will be set as
follows:
DISPLAY RX F
REQUENCY
EXP01 156.050 MHz
EXP02 —
EXP03 163.275 MHz
EXP04 155.050 MHz
EXP05 162.025 MHz
EXP06 163.575 MHz
WX10 163.275 MHz
(B) In CH70, ever time you are in transmit mode, (every
time you press PTT), the following test tone can be
outputted:
1st transmission: 1300 Hz
2nd transmission:2100 Hz
3rd transmission: Synthetic tone of 1300 Hz and 2100 Hz
4th transmission: Return to 1st transmission
(C) Scan the channels between WX10 and EXP04 in the
SCAN mode.

Starting Test Mode

Confirm that PWR/VOL switch is off, and short the TEST
points (JP1001). Turn on the PWR/VOL switch while press
and holding the [ DIST ] and [ DW ] keys.
VR1002
VR1001
VR1003
JP1001
TP1019
TC1001
T1005
10
TX F SCAN
REQUENCY
156.050 MHz X
157.425 MHz X
— X
155.050 MHz O
162.025 MHz X
158.975 MHz X
— O
MAIN UNIT A
Confirmation of VCO
— Confirmation —
r Connect the DC voltmeter to the test point (TP1019).
r Use the [ p ( UP )] / [ q ( DOWN )] key to set the channel
to EXP04, confirm that voltage on the test point is
over 1.0 V in the receive and transmit mode.
r Use the [ p ( UP )] / [ q ( DOWN )] key to set the channel
to EXP05, confirm that voltage on the test point is
below 5.0 V in the transmit mode.
r Use the [ p ( UP )] / [ q ( DOWN )] key to set the channel
to EXP06, confirm that voltage on the test point is
below 5.0 V in the receive mode.
Adjustment and Confirmation of Transmit Power
Adjust power at high and low in the transmit mode, and
confirm power in the specified bandwidth.
— Adjustment —
r Connect the wattmeter and 50-ohm dummy load to
the antenna jack.
r Use the [ H/L ] key to set transceiver to high power
and set the channel to CH16. With the PTT switch
pressed, adjust VR1001 so that RF power is 25 W.
r Use the [ H/L ] key to set transceiver to low power and
set the channel to CH16. With the PTT switch pressed,
adjust VR1002 so that RF power is 0.8 W.
P
LIGNMENT OINT
T1001
T1002
T1003
T1004