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 Satellite Internet forum › Dish pointing and alignment › Skew question
 Pages: 1

# Skew question

 Ex Member Ex Member Sep 7th, 2012 at 7:29am   I'm a bit confused over a polarisation matter. Heres the scenario.I commisioned two vsats the other day.One Looking East. The other looking West. Both in the Southern Hemi.I got the pol skew angle from the Service Provider. But what I thought I set right for the East looking dish didn't make sense.I would like to send an illustration of what I mean, its a little complicated to explain. How do I upload one?From what I know about pol, If in the southern Hemi, turn CCW for an east looking dish (looking into reflector), and CW for west. Then +- 90 if you need to. Back to top « Last Edit: Sep 8th, 2012 at 9:39pm by Admin1 »     IP Logged
 Ex Member Ex Member Reply #1 - Sep 7th, 2012 at 1:52pm   What you describe is possible, assuming the two installations were on two different satellites. A skew angle of zero is when the dish longitude and satellite longitude are identical. This is also the point where azimuth is 90. And for me it's easier to understand skew if I'm behind the dish. If your azimuth is less than 90 degrees, you're pointing left. Skew would be CCW (as viewed from behind). If your azimuth is more than 90 degrees, you're pointing right. Skew would be CW. This is true regardless of hemisphere. That said, it's important is to input the correct value (+ or -) of east and west latitude, north and south longitude into the Az/El/Pol formulas. Relative to east/west/north/south inputs, a (+) value where a (-) value should be will result in a pointing error, as will a (-) value where a (+) value should be. So the discrepancy might also be as simple as human error.//greg// Back to top IP Logged
 Ex Member Ex Member Reply #4 - Aug 22nd, 2013 at 12:51pm   I just want to return to this topic for a sec. and try to understand something more.I have a skew of +65, calculated from Satsig (and the same from others). I'm South of the equator so I'm pointing East. Now I'm consistently getting max Vertical Xpol at about +25. The diagram shows what I mean. Theoretically I should be a bit more CCW at +65. What do you think?Note: Andrew feed with xpol omt. Lnbs on both feed ports receive only. DVBS carrier using MER function on Signal Strength Meter to peak. Back to top xpol.JPG (18 KB | 321 )   IP Logged