TEST AND MEASUREMENT
Issue 1
Section 6
MCUK990801C8
Revision 0
– 42 –
Service Manual
PL0 (limits ±0.2dB)
NOTE:
Calibration data exists for GSM 1800 low and high channels, but is not used.
6.5.2 RSSI
This procedure describes the calibration of RSSI on the Mid-channel (Mch = Ch 60). This process must be carried out for LOW/
BOTTOM CHANNEL and HIGH/TOP CHANNEL. The following channel settings are used in this procedure:
1.
Set up the test equipment as described in Section 6.3 and switch the unit into test mode as described.
2.
Apply a carrier frequency of +68kHz to the telephone (for Ch 60 = 947.068 MHz) at an input level of -90 dBm.
3.
On the Channel box, highlight the CHANGE CH field and, press the left-right arrow keys until <60> is displayed in the
window. Press ENTER to select.
4.
Highlight the SET AGC 1 field and change the set value to 49 dB. Press ENTER.
5.
Highlight the RSSI dBm <> field and press ENTER.
Figure 6.19: RSSI dB field
6.
If the measured value is not -90 ±1 then make the following calculation:
RSSI offset value = [-(90+MEASURED RSSI VALUE)] x 2
= [-90-MEASURED RSSI VALUE] x 2,
for example
[-(90+(-95))] x 2
= [-90-(-95)] x 2
= 10
Record the result.
Channel
GSM900
GSM1800
Low/Bottom
1
544
Mid
62
698
High/Top
124
855
