XPD test

Hello,

During the link implementation of the RTN 950 XPIC link 1+0, QPSK, 7Mbps, 17GHz, achieving a XPD correct value was difficult in case of technical skills or hardware issues. Therefore, is not always easy to identify when the real problem of not achieving the XPD correct value comes because of the installation skills or a hardware defect. RTN 950 uses  5.83.03.31 version and IFX2 boards.

One recommended process to reach the calculated XPD value is:

1. 
   Adjust the azimuth angle and elevation angle of the antennas at both ends to achieve required RSL. Be sure that vertical IDUs are powered off and you are aligning the antenna by using Horizontal IDUs.
    

2. 
   Note down the RSL of Site-A (RSL1) on horizontally polarized IDU.
    

3. 
   Power off the Horizontal Radio on Site-B.
    

4. 
   Power on the vertically polarized ODU on Site-B.
    

5. 
   Note down the RSL of Site-A (RSL2) on horizontally polarized IDU.
    

6. 
   The calculated XPD (XPD = RSL2 – RSL1) should be 30 dB, if not then we have to align the feed horn to achieve the required value on site B.
    

7. 
   Loose up the screws that hold feed horns and rotate the feed horn slightly until the signal level reaches 30 dB.
    

8. 
   Note down the RSL of Site-B (RSL3) on Vertical polarized IDU.
    

9. 
   Power off the vertical Radio on Site-A.
    

10. 
    Power on the horizontally polarized ODU on Site-A.
     

11. 
    Note down the RSL of Site-B (RSL4) on vertically polarized IDU.
     

12. 
    The calculated XPD (XPD = RSL4 – RSL3) should be 30 dB if not then we have to align the feed horn to achieve the required value on site A.
     

13. 
    Repeat back from Step 7.
     

14. 
    If calculated XPD value can not be reached in both sides, then verify connections in IF cable, Vertical Horizontal wave guides feeders, Antenna or try replacing IFX2 boards.
     

Thanks