Larry, if I butchered a dish, I would be guilty of destruction, and that is not any intent I can fathom being. My fathoms here are dish design, and design is not quality, it is for purposes and technical matching. In design, certain qualities of a product are brought out, and such is the basis of quality when compared to other qualities.
What I am saying, however, is: If a dishes diameter has a larger distance top to bottom compared to side to side; more area of the dish is focused to the feed from the vertical (parabolic's), thus higher gain on vertical transponders compared to horizontal ones. This is a quality the parabolic's of a dishes design brings out. If the dish plates of this kind, normally mounted, higher than wider, were compared to the same dish plate, 90 degree's mounted instead, one would notice that the horizontal transponder's gain would increase, while the vertical ones would be less. This would also match the CONUS beam patterns and differences between, and though the most southerly satellite would show the biggest difference, and such is skewing this type of dishes feed for correct reception of any satellite not directly south accomplishes "area" of the dish a little to my point; it is the dishes design which shows that I could prove any weakness it has in Horizontal transponder reception. This weakness in design is also a strength, because if you look at the beam patterns across the World, in South America (although Brazil's beam pattern is blobular) it matches the Continent types BETTER (CONUS, a coned head, using parabolic's to achieve an prescribed area), Africa, same thing; weaker verticals than horizontals, dish better in gain for verticals would balance the act...
How bout this, I'll do it for you next time i'm in California; we'll set up both dishes, and you watch me buy and butcher my 90 cm. 90 degrees off, at my time and expense (not a clients). I'll prove the same thing I am saying. Horizontal and Vertical beams attenuate according to the amount of area they must cover (because of distances the signal must travel), and if the sent beam pattern is wider than it is high (N to S); then it is a property of the signal (sent by the satellite in space) that the horizontal transponders are weaker, when received, than the same powered transponders of the same satellite that are vertical, because they must travel farther (and attenuate more) to get where they are going to, such is the "parabolic's"