Tait TM8100 mobiles, Service Manual

Page: 263 / 620

TM8100/TM8200 Service Manual Receiver Fault Finding 263
© Tait Electronics Limited November 2007
Task 15 —
Noise Muting
Selected
With noise muting selected, check the noise mute settings:
1. In the calibration application open the
“Deviation/Squelch”
page and
click the
“Squelch and Signaling Thresholds”
tab.
2. Ensure that, under the “Squelch Thresholds” label, the settings in the
“Country”
,
“City”
and
“Hard”
fields are what the Customer expects.
3. Open the
“Raw Data”
page and click the
“Mute”
tab.
4. Compare the values in the
“Mute Noise Readings”
field with the
required minimum and maximum values listed in Table 10.5 .
5. If the mute noise readings are correct, go to Task 1 and check the
receiver sensitivity. If they are not, go to Step 6 .
6. Recalibrate the mute and then check if the mute fault has been
removed.
7. If the fault has been removed, go to “Final Tasks” on page 163 . If it
has not, go to Task 1 and check the receiver sensitivity.
Table 10.5 Mute data
Channel spacing SINAD (dB)
Mute noise readings
(K5 band)
Mute noise readings
(all other bands)
Minimum Maximum Minimum Maximum
Narrow (12.5 kHz) 8 1700 2000 1900 2300
20 200 450 250 500
Medium (20 kHz) 8 1400 2100 3700 4200
20 150 850 1000 1500
Wide (25 kHz) 8 3500 5600 5000 7300
20 1100 3100 2200 3700