Standard Horizon HX370S, Руководство по обслуживанию

Страница: 10 / 44

10
Before Alignment
ˆ
Press and hold in the [
T
] key and [ MEM ] key while
turning the transceiver on to enter the Alignment
Mode.
PLL Reference Frequency
ˆ
Set up the test equipment as shown below for PLL
and Ttransmitter Section Alignment. Maintain the
supply voltage at 8.4V DC for all steps.
ˆ
Press the [
S
] or [
T
] key to sect the display to “
rEF rEF
rEF rEF
rEF
.“
The transceiver now is in the PLL Reference Frequency
Alignment Mode.
ˆ
Press the [
PRESET
] key to enable adjustment of the
PLL Reference Frequency.
ˆ
Press the
PTT
key to cause the transceiver to trans-
mit; if necessary, press the [
S
] or [
T
] key to adjust
the frequency to 155.500 MHz (±100 Hz).
ˆ
Press the [
PRESET
] key to exit the PLL Reference Fre-
quency Alignment Mode.
Alignment
Squelch Threshold and Tight Squelch Adjustment
ˆ
Set up the test equipment as shown below for Receiver
Section Alignment. Maintain the supply voltage at
8.4V DC for all steps.
ˆ
Press the [
S
] key twice to set the display to “
tHL tHL
tHL tHL
tHL
.“
The transceiver now is in the Squelch Threshold Align-
ment Mode.
ˆ
Set the RF signal generator output to 155.600 MHz, at
a level of –12 dB
μ with ±3.5 kHz deviation with a 1
kHz audio tone.
ˆ
Press the [
PRESET
] key to read the Squelch Thresh-
old data.
ˆ
Press the [
H/L
] key twice.
ˆ
Press the [
PRESET ] key to exit the Squelch Thresh-
old Alignment Mode.
ˆ
Press the [
S
] key monentarily to set the display to
“
tI tItI
tI
tI
.“ The transceiver now is in the Squelch Tight Align-
ment Mode.
ˆ
Increase the RF signal generator output to –4 dB μ , then
press the [
PRESET ] key to read the Squelch Tight
data.
ˆ
Press the [
H/L
] key twice.
ˆ
Press the [
PRESET
] key to exit the Squelch Tight
Alignment Mode.
Inline
Wattmeter
RF Sampling
Coupler
AF Signal
Generator
8.4 V DC
Regulated Power Supply
50
Dummy Load
Ω
Frequency
Counter
Frequency
Counter
MIC GND
8.4 V DC
Regulated Power Supply
SINAD
Meter
RF Signal
Generator
8
Dummy Load
Ω
SP GND
PLL & T
RANSMITTER
S
ECTION
A
LIGNMENT
S
ETUP
R
ECEIVER
S
ECTION
A
LIGNMENT
S
ETUP