View Full Version : Skew? What is that?



PSB
09-13-2004, 06:03 PM
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.

Diamond Jim
09-14-2004, 08:06 PM
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~

PSB
09-14-2004, 08:15 PM
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!

timmy1376
09-19-2004, 08:00 PM
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.

PSB
09-19-2004, 08:32 PM
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.

PSB
04-18-2006, 08:48 PM
Sadouns Installation page about SKEW.........

http://www.sadoun.com/Sat/Installation/LNBF-Installation.htm

Reigster at SatelliteGuys