When u say skew. Do u mean that the probe inside feedhorn needs to be pointed at satellite? And the probe is rotated when im controlling polarity?
Correct. When you change between an odd and even channel using the analog receiver, the mechanical servo rotates the probe inside of feedhorn. The skew adjustment fine tunes the rotation of the polarity switching. When the dish is aimed to true south (the highest point of the arc), the probe will be straight up and down (12 o'clock position) when a vertical transponder is selected and rotated 90 degrees to the 3 o'clock position when tuned to a horizontal polarity transponder.
On 99w transponder frequency 4000 has a Horizontal polarity with a symbol rate of 26400. This means that the probe will be rotated to a horizontal position. 99w satellite is west of your location. So if you reference this
Satellite Aiming Calculation from
www.GeoSatFinder.com, you will note that the LNBF will not be physically pointed at the 3 o'clock position. When the dish is pointed at 99w, look into the feedhorn and the probe will be pointed at approximately the 4'oclock position.
Here is the theory... With the dish aimed due south at the highest point of the arc, the Vertical probe will be pointed straight up = 0 degrees. As the dish moves on the polar mount, the feedhorn rotates . When your dish is pointed to the west of the top of the arc at 99w, the vertical channel skew will be rotated by approximately 25 degrees. From your location looking west at the 99w satellite, a vertical transponder will actually be viewed at a +25 degrees with no adjustment of the polarization or skew setting on the analog receiver.
Now select a Horizontal polarity channel on the analog receiver. The servo will rotate the probe 90 degrees. When you look inside the feedhorn, you will see the probe appears to be oriented 90 + 25 = 115 degrees from a vertical plane. The right side of the probe will be lower than the left side. This is a positive 25 degree skew setting.
Now you say, "what a hassle just to change between the two polarities", and you are correct. This is why many dish owners have removed the Feedhorn/LNB configuration like your system has and replaced with a LNBF that automatically electronically switches between Horizontal and Vertical polarity with DVBS S2 receivers. Your current Feedhorn/LNB has better performance, but more of a hassle to use the analog receiver to select the correct polarity for the tuned channel.