Incorrect Rssi Readings - Tait TM8235 Service Manual

10.4

Incorrect RSSI Readings

Introduction
Task 10 —
AGC Voltage
Calibration
250 Receiver Fault Finding
If the RSSI readings are incorrect, the receiver calibration is suspect.
There are four tasks, which cover the four types of settings concerned:
Task 10: AGC voltage calibration
Task 11: FE tune BPF settings
Task 12: RSSI delta gain
Task 13: AGC delta gain
If the receiver is properly calibrated but the fault persists, then the receiver
sensitivity is suspect.
The first settings to check concern the AGC voltage calibration.
In the calibration application open the "Raw Data" page and click the
1.
"Receiver" tab.
Note the settings listed in the "AGC Voltage Cal Pts" field. The nominal
2.
settings should be as listed in
on which demod IC is fitted (IC400). The IC is either an RF9667 or
an RF2667.
3. If the settings are correct, go to
4. Recalibrate the receiver and check the settings again.
5. If the settings are now correct, go to
Task 1 and check the receiver sensitivity.
6. Check if the RSSI fault has been removed. If it has, go to
Tasks" on page
Table 10.3. The AGC values depend
Task 11. If they are not, go to
Step
157. If it has not, go to
Step
6. If they are not, go to
"Final
Task 11.
TM8100/TM8200 Service Manual
© Tait Electronics Limited June 2006
4.