BSC621 and BSC621-2 Technical Bulletin   Number bsc621t1

It has come to our attention that over tightening the "F" connector on the Ku LNBF may cause the entire Ku LNBF to turn inside the housing.  This causes the Ku polarity probes to be mis-aligned with the C polarity probes.  

The following instructions will fix this problem.  Please read the instructions completely through before attempting this fix.  Make sure you understand each step.  Only after you feel comfortable that you can perform this fix should you then proceed FOLLOWING THESE INSTRUCTIONS STEP BY STEP.  

At no time should you exert undue force on any of the screws, nuts, or any other part of the assembly.  DO NOT touch or try to adjust the probes and do not touch the inside of the wave guide.  The natural oils from your fingers can disrupt the performance of this device.

Click any picture to enlarge (opens in new window)
1.  Remove the plastic cap from the wave guide.  
2.  Look at the isolation bars, they should form a + and be offset by 90 degrees.  

If they are 90 degrees offset the Ku LNBF has not moved inside the housing and you do not need to proceed with this fix.  

If they are not 90 degrees offset proceed with this fix.  
3.  Carefully remove the 3 screws that hold the Ku housing on the C housing.  This is the only 3 screws on the device.
4.  Carefully remove the Ku housing.  You will see a water gasket between the two housings.  Note that it fits into a groove on the C housing.  Pay close attention to this gasket when re-assembling the housing.  
5.  Align the Polarity Mark with the Ku Probe and Isolation bar by turning the Ku LNBF inside the housing.  You may need to loosen the nut on the Ku "F" connector to allow the Ku LNBF to turn.  

After the alignment is complete, tighten the "F" connector nut against the housing being careful not to over tighten it.  Re-check your alignment and fine tune if needed.




This is a better picture of the Polarity Mark on the housing.
6.  Re-assemble the Ku housing to the C housing.  Take note of the formed area that allows room for the C "F" connectors and being careful to keep the water gasket in it's proper place.  

Replace the 3 screws that hold the Ku housing to the C housing.  

Replace the plastic cap.  

Your LNBF should now perform normally.  
This bulletin may be re-distributed provided it is not modified in any way.
DMS International - www.dmsiusa.com - email - Technical: 770-874-1079
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