Panasonic EB-GD30 - Manual (Page 55)

TEST AND MEASUREMENT
MCUK991001C8 Section 6 Issue 1
Service Manual – 49 – Revision 0
3. If the carrier leakage ratio is greater than 35 dBc then unit is OK. (offset calibration is complete).
4. If not then repeat steps 1, 2 and 3 above for Qch offset values: 87, 67, 47, 27, 7.
5. If the carrier leakage ratio is still less than 35 dBc then unit is a fail.
Q Inc Calibration
1. Set Qch offset to 167 (see Qch Check step 2).
2. Measure carrier leakage ratio.
3. If carrier leakage ratio is greater than 35 dBc then unit is OK. (offset calibration is complete).
4. If carrier leakage ratio is less than 35 dBc then repeat steps 1, 2 and 3 above for Qch offset values:187, 207, 227, 247.
5. If carrier leakage ratio is less than 35 dBc then unit is a fail.
I, Qch Gain
IMPORTANT: I, Qch offset calibration should be done before this calibration.
Spectrum Analyser Setup.
centre frequency = 902.4 MHz
RBW = 10 kHz
VBW = 10 kHz
span = 1 MHz
sweep time = 2 sec
1. Set the Channel box controls to channel 62 at power level 5, normal burst modulated with all 1’s.
a. Press the down arrow until CHANGE CH > is highlighted and then press ENTER.
b. Press the down arrow until PL is highlighted. Press ENTER.
c. Press the down arrow until TX DATA is highlighted. Press the move arrow until 1 appears in the highlighted field. Press
ENTER.
2. Using the spectrum analyser measure the image leak ratio. Image leak ratio is the measured ratio of peak power and the
power at 135 kHz below peak frequency.
Example:
peak power (902.468 Mhz) = 33 dBm
power at 135 kHz below peak power = -9 dBm
image leak ratio = 33 dBm - (-9 dBm) = 42 dBm
Figure 6.31: Image leak ratio
3. If image leak ratio is greater than 30 dBc then unit is OK. (offset calibration is complete).
4. If image leak ratio is less than 30 dBc then go to Ich gain calibration.