Part 3.4 : The RX IF Synthesiser
The IF Synthesiser can be checked with the receiver set to the same setting as
previously described. Please refer to figure 3.4: The RX IF Synthesiser
for the
relevant control voltages and RF levels.
Figure 3.4 : The RX IF Synthesiser
DIV
13
LOOP
FILTER
DIV 180
IC201 LMX2331L IF-PLL
PHASE
COMPARATOR
23-24
PHASE
DIFFERENCE
(CURRENT)
PHASE
DIFFERENCE
(VOLTAGE)
13MHz
CLK
8
1Mhz
1Mhz
GND
IC300
32
33
34
35
DIV3
18
16
180Mhz
180Mhz
D303B
D303A
540Mhz
PUPLO2
31
DIV2
To RX Demodulator
Part 3.5 : Receiver demodulated I and Q Signals
When it has been established that all the afore mentioned signals, supplies and
RF levels are correct, then on IC300 (pins 39,40,45 & 46) there should be output
the demodulated I and Q signals. These are then presented to the logic board for
conversion into data. Please refer to figure
3
for the correct waveform shape
and characteristics.
Note:
When checking the PCN RX I & Q’s, the RF gen level must be reduced to a
value of -68 dbm’s so that the signal measured will match the one
displayed in Fig.4.1. Otherwise the Peak-Peak voltage levels of the
measured signal and that in Fig.4.1 will be of differing amplitudes.
1.5 V.d.c
- 19 dbm @
180 Mhz
2.8 V.d.c
Summary of Contents for DB2000
Page 1: ...DB2000 Service Manual Help ...
Page 3: ... ...
Page 5: ... 2 3 4 2 2 2 2 2 0 0 0 5 3 4 2 6 2 7 2 2 2 2 0 8 9 2 2 2 2 2 2 2 2 ...
Page 7: ... 2 6 2 2 2 2 2 3 4 2 2 0 2 ...
Page 8: ... 2 ...
Page 9: ... Previous Section Next Section Main Menu Section 2 Unit Specifications ...
Page 77: ... 1 2 ...
Page 83: ...Fit Antenna INSERT AND SCREW THE ANTENNA INTO THE ASSEMBLY ...
Page 107: ...Fig 3 7 GSM_LNA Pg 3 3I TP419 Fig 3 8 PCN_LNA Pg 3 3J TP420 Fig 4 9 TCXO Pg 2 H11 TP413 ...
Page 109: ...Fig 4 3 PCN_TX Pg 1 1J TP417 Fig 4 4 3V_G_TX Pg 1 4I TP100 Fig 4 5 3V_P_TX Pg 1 4J TP101 ...
Page 110: ...Fig 4 6 GSM_ON Pg 1 2K TP402 Fig 4 7 PCN_ON Pg 1 1K TP415 Fig 4 8 PRE_ON Pg 1 4J TP416 ...
Page 112: ... I Q ...
Page 113: ...Fig 4 14 V_ERROR PCN Pwr Lvl 7Pg 1 16I Fig 4 15 300khz Charge Pump Pg 1 Log 9G ...
Page 115: ... Previous Section Next Section Main Menu Section 6 Device Device Information Information ...
Page 172: ......
Page 173: ......
Page 174: ......
Page 175: ......
Page 176: ......
Page 177: ......
Page 178: ......
Page 179: ......
Page 180: ......
Page 181: ......
Page 182: ......
Page 183: ......
Page 184: ......
Page 185: ......
Page 186: ......
Page 187: ......
Page 188: ......
Page 189: ......
Page 190: ... Previous Section Next Section Main Menu Glossary of Terms ...