250
Receiver Fault Finding
TM8100/TM8200 Service Manual
© Tait Electronics Limited
June 2006
10.4
Incorrect RSSI Readings
Introduction
If the RSSI readings are incorrect, the receiver calibration is suspect.
There are four tasks, which cover the four types of settings concerned:
■
: AGC voltage calibration
■
: FE tune BPF settings
■
: RSSI delta gain
■
: AGC delta gain
If the receiver is properly calibrated but the fault persists, then the receiver
sensitivity is suspect.
Task 10 —
AGC Voltage
Calibration
The first settings to check concern the AGC voltage calibration.
1.
In the calibration application open the
“Raw Data”
page and click the
“Receiver”
tab.
2.
Note the settings listed in the
“AGC Voltage Cal Pts”
field. The nominal
settings should be as listed in
. The AGC values depend
on which demod IC is fitted (IC400). The IC is either an RF9667 or
an RF2667.
3.
If the settings are correct, go to
. If they are not, go to
4.
Recalibrate the receiver and check the settings again.
5.
If the settings are now correct, go to
. If they are not, go to
and check the receiver sensitivity.
6.
Check if the RSSI fault has been removed. If it has, go to
. If it has not, go to
Summary of Contents for TM8235
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 04 Issue 4 June 2006...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 62: ...62 Description TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 148: ...148 Disassembly and Reassembly TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 162: ...162 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 178: ...178 Interface Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 258: ...258 Receiver Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 446: ...446 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...