Standard Horizon HX400, Service Manual

Page: 8 / 40

HX400 Service Manual
Alignment
Alignment - 4
Squelch Threshold Adjustment (Wide Band-
width)
1. Press the [
p
] or [
q
] key to
select the display to “ N TH
W ”.
2. Press the [ SQL ] key to enable
adjustment of the Squelch Threshold level.
3. Press the [
p
] or [
q
] key to
select a small character of
lower right corner of the dis -
play to “ C ”.
4. Set the RF Signal Generator output level –8
dBμV (with a standard FM modulation: ±3.0
kHz deviation @ 1 kHz) at 156.800 MHz.
5. Press the [ H/L ] key to read the Squelch Thresh -
old level, then press and hold the [ H/L ] key for
2 seconds to save the Squelch Threshold level at
the band center.
6. Press the [
p
] key to change
the “ C ” character to “ H ” at
the lower right corner of the
display.
7. Change the RF Signal Generator to 174.000
MHz. The output level keeps –8 dBμV (with a
standard FM modulation: ±3.0 kHz deviation @
1 kHz).
8. Press the [ H/L ] key to read the Squelch Thresh -
old level, then press and hold the [ H/L ] key for
2 seconds to save the Squelch Threshold level at
the high band edge.
9. Press the [
q
] key twice to
change the “ H ” character to
“ L ” at the lower right corner
of the display.
10. Change the RF Signal Generator to 134.000
MHz. The output level keeps –8 dBμV (with a
standard FM modulation: ±3.0 kHz deviation @
1 kHz).
11. Press the [ H/L ] key to read the Squelch Thresh -
old level, then press and hold the [ H/L ] key for
2 seconds to save the Squelch Threshold level at
the low band edge.
12. Press the [ CLR(WX) ] key to exit from this align -
ment item.
Squelch Threshold Adjustment (Narrow Band-
width)
1. Press the [
p
] or [
q
] key to
select the display to “ N TH
N ”.
2. Press the [ SQL ] key to enable
adjustment of the Squelch Threshold level.
3. Press the [
p
] or [
q
] key to
select a small character of
lower right corner of the dis -
play to “ C ”.
4. Set the RF Signal Generator output level
–8 dBμV (with a standard FM modulation:
±1.5kHz deviation @ 1 kHz) at 156.800 MHz
5. Press the [ H/L ] key to read the Squelch Thresh -
old level,then press and hold the [ H/L ] key for
2 seconds to save the Squelch Threshold level at
the band center.
6. Press the [
p
] key to change
the “ C ”character to “ H ” at
the lower right corner of the
display.
7. Change the RF Signal Generator to174.000
MHz. The output level keeps –8 dBμV (with a
standard FM modulation: ±1.5 kHz deviation @
1 kHz).
8. Press the [ H/L ] key to read the Squelch Thresh -
old level,then press and hold the [ H/L ] key for
2 seconds to save the Squelch Threshold level at
the high band edge.
9. Press the [
q
] key twice to
change the“ H ” character to
“ L ” at the lower right corner
of the display.
10. Change the RF Signal Generator to134.000
MHz. The output level keeps –8 dBμV (with a
standard FM modulation: ±1.5 kHz deviation @
1 kHz).
11. Press and hold the [ H/L ] key for 2 seconds to
read the Squelch Threshold level at the low
band edge.
12. Press the [ CLR(WX) ] key to exit from this align -
ment item.