Panasonic G600 Service Manual page 72

I, Qch Gain
IMPORTANT: I, Qch offset calibration should be done before this calibration.
Spectrum Analyser Setup.
centre frequency = 902.4MHz
RBW = 10kHz
VBW = 1kHz
span = 1MHz
sweep time = 2sec
1. Set the Channel box controls to channel 62 at power level 5, normal burst modulated with all 0'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 O appears in the
highlighted field. Press ENTER
2. (Figure 28) Using the spectrum analyser measure the image leak ratio. Image leak ratio is the measured ratio
of peak power and the power at 135kHz below peak frequency.
Example:
peak power (902.468Mhz) = 33dBm
power at 135kHz below peak power = -9dBm
image leak ratio = 33dBm - (-9dBm) = 42dBm
Figure 28: Image leak ratio
3. If image leak ratio is greater than 30dBc then unit is OK. (offset calibration is complete).
4. If image leak ratio is less than 30dBc then go to Ich gain calibration.
IQch Gain Calibration
1. Set IQch gain to -0.25dB.
a) On the Channel box press F6.
b) (Figure 26) Press move left arrow until IQCH GAIN field is highlighted. Press ENTER.
c) (Figure 27) Enter 2 into the data field. Press ENTER.
2. Measure the image leak ratio.
3. If image leak ratio is greater than 30dBc then unit is OK. (offset calibration is complete)
4. If image leak ratio is less than 30dBc then repeat steps 1, 2 and 3 above with IQch gain values: -0.50dB, -
0.75dB.
5. If image leak ratio is still less than 30dBc then the unit is a fail.
MCUK980101C8
Service Manual
http://cxema.ru
Section 7
7 - 19
TEST AND MEASUREMENT
600-0726
Issue 1
Revision 0