Standard Horizon HX290, Руководство по обслуживанию

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10
HX290 Service Manual
Before Alignment
Remove the Front Panel from the transceiver according
to the following procedures:
1. Disconnect the antenna from the transceiver.
2. Remove the VOL knob, MIC/SP Screw (with Rubber
Cap), and Battery Pack from the transceiver.
3. Remove the two screws which located at the bottom
side on the battery compartment of the transceiver.
4. Carefully pull out the chassis from the Front Panel.
Refer to the “Exploded View“ on the page 4.
Reference Frequency Adjustment
Set up the test equipment as shown below, and set the
DC Power Supply voltage to 7.4 V.
Turn the transceiver on.
Set the channel to CH16.
Use the key to set the transceiver to “LOW” power.
With the PTT switch pressed, adjust VR1002 so the
Frequency Counter reading is 156.800 MHz ± 100 Hz.
Release the PTT switch.
Transmit Power Adjustment
Set up the test equipment as shown below, and set the
DC Power Supply voltage to 7.4 V.
Set the channel to CH16.
Use the key to set the transceiver to “HI” power.
With the PTT switch pressed, adjust VR1003 so that
RF output power is 5.0 W ± 0.1 W.
Release the PTT switch, then set the transceiver to
“LOW” power by pressing the key.
With the PTT switch pressed, adjust VR1001 so that
RF output power is 0.9 W ± 0.1 W.
Release the PTT switch.
TX Deviation Adjustment
Set up the test equipment as shown below, and set the
DC Power Supply voltage to 7.4 V.
Set the AF Signal Generator output to 100 mVrms at 1
kHz.
Set the channel to CH16 with “LOW” power.
With the PTT switch pressed, adjust VR1004 so that
the maximum deviation is 4.2 kHz ± 0.1 kHz.
Release the PTT switch.
Turn the transceiver off.
Alignment
TX S
ECTION
A
LIGNMENT
S
ETUP
RF Sampling
Coupler
Inline
Wattmeter
Deviation
Meter
50
Dummy Load
Ω
Frequency
Counter
AF Signal
Generator
VR1001
VR1003
VR1002
VR1004
Regulated
Power Supply
AF Signal Generator
GND