Pll Section; Receiver Section; Squelch Gain Adjustment - Standard Horizon HX400 Service Manual

PLL Section

PLL Reference Frequency Adjustment
1. Connect the wattmeter, dummy load, and fre-
quency counter to the antenna jack.
2. Press the [p] or [q] key to
select the display to "REF".
3. Press the [SQL] key, then
press the [H/L] key to enable
adjustment of the PLL Refer-
ence Frequency.
4. Press the PTT key to transmit
the transceiver, if necessary,
press the [p] or [q] key to adjust the frequency
so the counter frequency is 156.800 MHz (±100
Hz).
5. Press and hold the [H/L] key for 2 seconds to
save the new setting.
6. Press the [CLR(WX)] key to exit from this align-
ment item.

Receiver Section

Squelch Gain Adjustment

1. Connect the RF Signal Generator to the antenna
jack, and connect the DC voltmeter to TP4032
or TP5032.
2. Press the [p] or [q] key to
select the display to "GAIN".
3. Press the [SQL] key to enable
adjustment of the Squelch
Gain level.
4. Press the [p] or [q] key to
select a small character of
lower right corner of the dis-
play to "C".
5. Set the RF Signal Generator output level 0
dBμV (with a standard FM modulation: ±3.0
kHz deviation @ 1 kHz) at 156.800 MHz.
6. Press the [H/L] key, then press the [p] or [q]
7. Press and hold the [H/L] key for 2 seconds to
8. Press the [p] key to change
9. Change the RF Signal Generator to 174.000
10. Press the [H/L] key, then press the [p] or [q]
11. Press and hold the [H/L] key for 2 seconds to
12. Press the [q ] key twice to
13. Change the RF Signal Generator to 134.000
14. Press the [H/L] key, then press the [p] or [q]
15. Press and hold the [H/L] key for 2 seconds to
16. Press the [CLR(WX)] key to exit from this align-
TP4032
or
TP5032
Alignment - 3
key so that the DC voltmeter reading is 0.3 V
(±0.05 V).
save the new setting at the band center.
the "C" character to "H" at
the lower right corner of the
display.
MHz. The output level keeps 0 dBμV (with a
standard FM modulation: ±3.0 kHz deviation @
1 kHz).
key so that the DC voltmeter reading is 0.3 V
(±0.05 V).
save the new setting at the high band edge.
change the "H" character to
"L" at the lower right corner
of the display.
MHz. The output level keeps 0 dBμV (with a
standard FM modulation: ±3.0 kHz deviation @
1 kHz).
key so that the DC voltmeter reading is 0.3 V
(±0.05 V).
save the new setting at the low band edge.
ment item.
Alignment
HX400 Service Manual