Skew? What is that?

Discussion in 'FTA / MPEG2 FAQ's' started by PSB, Sep 13, 2004.

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  1. PSB

    PSB Thread Starter On vacation

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    Skew - Polarity

    When you set the skew (Polarity) on your LNBF you are lining up your dish exactly to the same horizontal/vertical position as the satellite in the sky. The satellites all lie in a curve in the sky ( Clarke Belt ) and so are at different heights. Ku satellites use Horizontal and Vertical liner polarization and so the skew has to match the (H/V) position of the satellite for optimum satellite signal strength/quality.

    When standing in front of your dish, rotate the LNBF anti-clockwise for
    + skew values.

    Rotate the LNBF clockwise for - skew values.

    When the LNBF is straight up and down it is in the zero position.

    Keep your LNBF in the zero position when using a motor mount.

    This info is relevant only for liner Ku band LNBF.

    Polarization is not a factor with circular (L/R) polarized DBS LNB.
    On a multi LNB DBS satellite dish (Phase III / Dish 500...) the reason the skew is set is to simply level or align the LNB'S with the satellites in the sky.
     
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  2. Diamond Jim

    Diamond Jim SatelliteGuys Family

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    Pete,

    I always thought skew was the same thing as polarity. When I hit the auto skew isn't is spinning the little hook around inside the feed horn for horizontal or vertical? Set me straight, I would hate to think I have been wrong for 20 years.

    ~J~
     
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  3. PSB

    PSB Thread Starter On vacation

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    With C band systems yes, but with a smaller fixed dish the LNB is rotated by hand to the correct skew/polarity then clamped in position, with a KU motorised dish the LNB is set in the zero position and the dish sets its own skew as it turns and tilts, another great reason to have a motorized dish. As someone pointed out the other day they are getting a motorised system not just for the FTA channels but its a great way to keep up to date with whats going on with EVERY satellite up there!
     
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  4. timmy1376

    timmy1376 Active SatelliteGuys Member

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    Peter,
    I should have a PCI DVB card this week (because it was cheap) and I am going to see if WGN-DT is still in the clear on Nimiq 2 at 82 degrees. According to a site I went to to help point my old Dish net dish(DBS, single lnb), it says the skew is -17.11 Do I really have to do that? I am thinking no based on your first post here.
     
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  5. PSB

    PSB Thread Starter On vacation

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    No need to bother with skew on a DBS satellite, straight up and down will work for the DBS LNB, same as DirecTV single dish.

    I find even a DBS signal gets stronger when the dish is on a motor mount as the dish tilts as it swings and collects slightly more signal.
     
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  6. PSB

    PSB Thread Starter On vacation

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