LXT314
ALIGNMENT PROCEDURE
Page 1
1. REFERENCE TEST EQUIPMENT
A. HP8921A Cell site test set or HP8920A, B Communication Test Set with Spectrum
Analyzer option.
B. Fluke 187 Digital Voltmeter
C. HP E3615A Power supply
2. TEST POINT
A. ANTENNA
: Test point is not prepared. Use antenna contact with
ANTENNA_GND_T(antenna ground).
B. VCO reference voltage
: Test point 1 is prepared.
C. RX audio output
: Test point SPKOUT is prepared or use ear-jack(3.5mm).
D. TX Mic. Input
: Test point MICIN is prepared or use ear-jack(2.5mm) with 10uF
coupling capacitor.
E. Battery Vcc
: Test point is not prepared. Please use mechanical contact.
F. Up Key
: Test point UP is prepared.
G. Down Key
: Test point DW is prepared.
H. Function Key
: Test point Menu is prepared.
I. Monitor Key
: Test point SCAN is prepared.
J. PTT Key
: Test point PTT is prepared.
K. CALL Key
: Test point CALL is prepared.
Note. : All key can be activated when connect with ground.
3. VCO ALIGNMENT
A. Set unit to Channel 1 and connect a voltmeter to TP1 (VCO PD).
B. Press & hold PTT.
C. Extend L303 until the voltmeter reads 2.0V.
D.
Cover shield-plate on VCO can and monitor the voltage on TP1.
The voltage should be
1.5Vdc +/-0.2Vdc. If the voltage is not 2.0Vdc +/-0.2Vdc, realign L303 until meet to
requirement.
E. Release PTT button so units is in receiving mode and monitor the voltage on TP1. The
voltage should be in the range 2.0Vds +/-0.5V
F. Set unit to channel 14.
6. Press & hold the PTT switch and observe the voltage on TP4. The voltage should be 2 –
3,5 Vdc.
7. Release PTT and observe the voltage on TP4. The voltage should read between 2.0 - 3.5
Vdc.
Note : VCO shield-can should be soldered after VCO alignment is finished.
4. TRANSMITTER FREQUENCY ALIGNMENT
A. Press & hold the PTT button.
B. Align CT201 trimmer capacitor such that the output frequency is equal to the channel
frequency with a maximum error of +/- 200 Hz. CT201 is located on the left side of
20.95MHz X-tal.
