Standard Horizon HX471S, Service Manual

Page: 12 / 66

12
Alignment
Alignment Procedure
Before alignment, disconnect the antenna from the
transceiver using the Special Screw Driver.
Set up the test equipment as shown for transmitter
alignment.
Maintain the supply voltage at 8.4V DC for all steps.
To set up Alignment mode, press the [
], [
MEM
] and
[
16/9
] key while turning the transceiver on.
PLL Reference Frequency
With the wattmeter, dummy load and frequency
counter connected to the antenna jack.
Press the [
] or [ ] key to select the display to [
PLL
REF
**
] ([
**
] is “ 00 ” to “ FF ” Hex data). The radio now
is in the Reference Frequency Alignment Mode.
Press the [ MENU
] key to enable adjustment of the PLL
Reference Frequency.
Press the PTT key to transmit the transceiver, if neces-
sary, press the [
] or [ ] key to adjust the frequency
so the counter frequency is 467.7125 MHz (±100 Hz).
Press the [ MENU
] key to exit this Alignment Mode.
Receiver Circuit
Set up the test equipment as shown below for receiver
alignment.
Maintain the supply voltage at 8.4V DC for all steps.
Sensitivity & Squelch Threshold (Marine Band)
Press the [
] key to select the display to [
MARINE SQL
**
] ([
**
] is “ 00 ” to “ FF ” Hex data). The radio now is in
the Alignment Mode of the Sensitivity & Squelch
Threshold of the Marine Band.
Set the RF signal generator output to 158.510 MHz, at
a level of –8dBµ with ±3.5 kHz deviation with a 1 kHz
audio tone.
Confirm that the SINAD meter reading is better than –
12dBµ.
Rotate the SQL knob to the 10 o’clock position and
press the [ MENU
] key.
Reduce the RF signal generator output to –13dBµ, then
press the [
SCAN
] key to read the Squelch Threshold
data.
Press the [ SCAN
] key again to save the new setting .
Press the [ MENU
] key to exit this Alignment Mode.
PLL & Transmitter Section Alignment Setup Receiver Section Alignment Setup
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
SINAD
Meter
8.4 V DC
Regulated Power Supply
RF Signal
Generator
8
Dummy Load
Ω
SP GND