Before Alignment; Pll Reference Frequency - Standard Horizon HX370SAS Service Manual

Vhf/fm marine handheld transceiver
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Alignment

Before Alignment

Press and hold in the [ ] key and [ MEM ] key while
turning the transceiver on to enter the Alignment
Mode.

PLL Reference Frequency

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

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