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ADJUSTMENT PROCEDURE
Step Item
Adjustment
Procedure
1, PLL
L302,
L307
R
X PD voltage=1.6V TX PD voltage =2V, at CH16
2
TX Frequency
VC2
Adjust VC2 to obtain demanded TX frequency.
±
200Hz
3
TX Power Hi
VR5
Adjust VR5 to obtain demanded TX power 23
±
2W.
4
TX Power Low
VR6
Adjust VR6 to obtain demanded TX power 0.8
±
0.1W
5
TX Deviation
VR3
1.
Inject an audio frequency (AF) –20dBm.
2.
Adjust VR3 to obtain maximum TX deviation
≤
5kHz.
3. Check MIC modulation sensitivity, which should be
2.5~10 mV
6
RX Sensitivity
L10, L11, L12,
L13, L14, L19,
T1, T2, T3
1. Check RX sensitivity if it is normal.
2. Adjust L10, L11, L12, and L13 to obtain Best Frequency
response.
3. Adjust T1, T2 to obtain Best Frequency response.
4. Adjust L14, L19 to obtain Best sensitivity.
5. Adjust T3 to obtain Best SIAND AND Distortion. When at
antenna terminal input 1mV RF signal and modulated with
normal test modulation.
6. Repeat step 1 to 5.at CH28 and CH3.
7
DSC test
Check Modulation index for DSC. Modulation index for DSC.
Frequency error (demodulated DSC signal)
8
ATIS test
Check Modulation index for ATIS. Modulation index for ATIS.
Frequency error (demodulated ATIS signal)
