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<blockquote data-quote="a33" data-source="post: 1076839" data-attributes="member: 332642">Well. I guess there's two things going on here.One is the Phase Center of the feedhorn, not positioned at the focal point. That is crucial to correct, I would say.The other is the aiming point for the LNB. I've read about tests (some French tests, I believe) that the best results were gotten somewhere between the G-spot (at the end of the bisector line between AF and BF) and the deepest point of the dish (which lies, of course, between G-spot and middle of the dish).Of course when aimed at the G-spot, spill-over will be least.However signal density (per degree) at the LNB will get higher, when aiming higher at the offset dish (due to the fact that the dish surface is further away from the LNB ).So I guess some compromise between these effects would be best.(I don't know the size of the effect of the worse X-Pol, when thus using a 'higher offset angle'.)Therefore I am not holding the position that the G-spot should always be the aiming point, I believe a bit higher is also plausible.I never tested this myself, I must confess.But above the deepest point is indeed a no-go, I would say.Greetz,A33</blockquote>

[QUOTE="a33, post: 1076839, member: 332642"] Well. I guess there's two things going on here. One is the Phase Center of the feedhorn, not positioned at the focal point. That is crucial to correct, I would say. The other is the aiming point for the LNB. I've read about tests (some French tests, I believe) that the best results were gotten somewhere between the G-spot (at the end of the bisector line between AF and BF) and the deepest point of the dish (which lies, of course, between G-spot and middle of the dish). Of course when aimed at the G-spot, spill-over will be least. However signal density (per degree) at the LNB will get higher, when aiming higher at the offset dish (due to the fact that the dish surface is further away from the LNB ). So I guess some compromise between these effects would be best. (I don't know the size of the effect of the worse X-Pol, when thus using a 'higher offset angle'.) Therefore I am not holding the position that the G-spot should always be the aiming point, I believe a bit higher is also plausible. I never tested this myself, I must confess. But above the deepest point is indeed a no-go, I would say. Greetz, A33 [/QUOTE]

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