I dec calibration, I inc calibration, Qch check – Panasonic EB-GD30 User Manual
Page 54: Q dec calibration
TEST AND MEASUREMENT
Issue 1
Section 6
MCUK991001C8
Revision 0
– 48 –
Service Manual
4.
Enter 147 for Ich OFFSET and press ENTER.
Figure 6.30: I,Q data field selection 4
5.
Using the Spectrum Analyser, measure the new carrier leakage ratio.
6.
If the new carrier leakage ratio is greater than 30dBc then the unit is OK (offset calibration is complete).
7.
If the original carrier leakage ration (see I,Q OFFSETS step 2) is greater than the new carrier leakage ratio go to I Dec
Calibration.
8.
If the original carrier leakage ratio is less than the new carrier leakage ratio go to I Inc Calibration.
I Dec Calibration
1.
Set Ich offset to 107 (see Ich Check step 2).
2.
Using the spectrum analyser measure the new carrier leakage ratio.
3.
If the carrier leakage ratio is greater than 30dBc then unit is OK (offset calibration is complete).
4.
If not then repeat steps 1, 2 and 3 above for Ich offset values: 87, 67, 47, 27 and 7.
5.
If the carrier leakage ratio is still not greater than 30dBc then go to Qch Check.
I Inc Calibration
1.
Set Ich offset to 167 (see Ich check step 2).
2.
Using the spectrum analyser measure the carrier leakage ratio.
3.
If the carrier leakage ratio is greater than 30dBc then the unit is OK. (offset calibration is complete).
4.
If not then repeat steps 1, 2 and 3 above for Ich offset values: 187, 207, 227, 247.
5.
If the carrier leakage ratio is still not greater than 30dBc then go to Qch Check.
Qch Check
1.
Set Ich offset to 127.
2.
Set Qch offset to 147.
a. At the Channel box press F6.
b. Press move down arrow until QCH OFFSET appears in the field. Press ENTER.
c. Enter 3 into the data field and press enter.
3.
Measure the new carrier leakage ratio.
4.
If the carrier leakage ratio is greater than 35 dBc the unit is OK. (offset calibration is complete).
5.
If the original carrier leakage ratio (see I, Q ch Offsets step 2) is greater than new carrier leakage ratio then go to Q Dec
Calibration.
6.
If the original carrier leakage ratio is less than new carrier leakage ratio then go to Q Inc Calibration.
Q Dec Calibration
1.
Set Qch offset to 107 (see Qch Check step 2).
2.
Measure carrier leakage ratio.