Satellite Internet Forum.

Welcome, Guest.        Forum rules.
      Home            Login            Register          
Pages: 1

linkstar activation problem

(Read 3480 times)
Ex Member
Ex Member

Mar 4th, 2007 at 11:41pm  
I have linksar modem and I have installed it in Iraq on w6
im pointing the dish correctlly and im obtain good signal 0.0000x. All my parameters are correct and the sat led blinking slow one minute and blinking fast and go ready to activate when Bentley-Walker activate my modem the sat led become solid and I'm receive the service, but after 30 minute my modem restart and the sat led blinking slow and not blinking fast never when I check the pconf and the parameter I see no change in the parameter but I see a new two parameter as shown:
DVBMode              DVBS1    vcoplan             0
I'm trying to talk with Bentley Walker them answer was (the difference between the co and cross pol only 3dB this should be 20dB we need to improve this by 17dB)
im checked my dish and buc and lnb pointing is good and the signal is good and the sat led still blinking slow
aftar that I'm try to connect a new modem on same dish and same parameter the modem blinking slow one minute aftar that bilinking fast normally.
Can you tell me where the problem please and thank you.

my modem status:
   RSCorrectedErrorCount         4    RSUncorrectedErrorCount       4
   QPSKBER           0.00004848719    I2CErrorCount                 0
   LostSyncCount                 0    TimeSynced                  428
   MaxTimeSynced               428    Synced                        1
   TimeUnSynced                  0    NCODeviation                -16
   CarrDeviation       0.003438673    VCOLocked                     0
   CodeRate                    5/6    CarrierPhase             LOCKED
   RSVit                    LOCKED    UCActive             NOT ACTIVE
   Rs                     27.50000    Fs                           85
   frequency                  1616    UCLoaded                      1
   RxPower               -38.02674    RSFrameLength                 0

BER 0.00004848719
KSET BootConf
 Item 1. Addr 21b020, Key 0 0x0 ItemMark 1 ArrayPos 0
   termid                   0xcce7    popid                 0x1360050
   ctlPID                   0x1ffc    pcrPID                    0x365
   TDMCarrierFreq          1616660    SymbolRate             27500000
   MaritimeEnabled               0    Latitude                      0
   Longitude                     0    TxPower                     -28
   ODUStatus              INTERNAL    VCXOPar1                    0x0
   VCXOPar2                    0x0    TimingLoopBW                0x0
   Signature                   0x0    isEncryptionEnabled           0
   isRnccKeyValid                0    isRcstKeyValid                0
   PointingTool                  0    LNBVoltage                    0
   LNBVoltageIncrease            0    LNBToneOn                     0
   DVBMode                   DVBS1    vcoplan                       0

0xCCE7 SW rcst4s-2.1.0201.term.exe (PE) rcst4-2.0.0106.term.exe ()
0xCCE7 FW rcst.09150417.altera.dat () rcst.14140306L.altera.dat (PE)
LMFTPEXEC is the file stream management component on the terminal
File download is enabled
Number of incomplete files: 0
Streams being received:
KSET 0x23ce50

Wish list:
KSET 0x23cf60
Back to top
« Last Edit: Apr 16th, 2007 at 12:04pm by Admin1 »  
IP Logged
Eric Johnston
Senior Member

Posts: 2109
Reply #1 - Mar 5th, 2007 at 9:42am  
Regarding " (the difference between the co and cross pol was only 3dB, this should be 20dB, we need to improve this by 17dB) "

This suggests that you have not yet aligned the polarisation adjustment angle at all.  Turn your transmit off as it will be seriously interfering with other peoples' services.   You need to start by setting your receive polarisation to nominal (vertical or horizontal).  

As an example, this LNB input waveguide is set to the nominal horizontal polarisation starting position:
It does not matter which side is the dipole probe - horizontal polarisation is with the broad faces of the waveguide on either side. Remember this is only the starting position.   If you have been told to receive nominal vertical polarisation then the starting position is with the broad faces on top and underneath.

Then adjust the feed rotation angle as required to 1 deg accuracy.  Positive adjustment means clockwise, while facing the satellite.  You should be aiming for better than 20 dB cross-pol isolation, 30 dB may be acheiveable if BW can measure it that well.  It is a very deep narrow null within about +/- 1 deg rotation of the exact angle.  The NOC may help you if you get under the feed arm and reach up to turn the feed by microscopic amount while they make a measrement.  Each cross-pol measurement may take 20 seconds, so be patient.

Use this page to get the required polarisation angle:
Best regards, Eric.
Back to top
« Last Edit: Apr 16th, 2007 at 12:21pm by Admin1 »  
IP Logged
Ex Member
Ex Member

Reply #2 - Apr 16th, 2007 at 8:37am  

I think there was a misunderstanding between you and Bentley Walker NOC. Probably they did not mean co and cross pol.  What they meant you need to adjust your polarisation "cross pol isolation".

If you go to the following link http://www.satellite-calculations.com/ and go to "antenna look angle" you can find out what is exactly the polarization angle to your GPS location.

As far as the terminal came up for few mins and then came down. one of the explanation for this, is most ISPs they have a small return carrier which they usually use to test low transmission terminals. and of course they cant relay on it and keep you there to operate. This is just done for test, and once you have the correct BER and Tx power values they move you to bigger carriers.

Anyway you need to cooperate with them to improve your TX, by cross pol or other methods.

Support Engineer
Back to top
« Last Edit: Apr 16th, 2007 at 11:57am by Admin1 »  
IP Logged
Pages: 1