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<blockquote data-quote="a33" data-source="post: 1027389" data-attributes="member: 332642">Well, Rima, I'm no expert on triax dishes, but is it possible to do a string test on the working area of the TD110?Maybe the rim of the dish, though perfectly flat at the front of the dish, has different 'heights' to the working area of the dish?I've seen a picture of such a dish once, and it would explain a lot.For that reason I would prefer the calculation of offset angle by measuring the deepest point of the dish (compared to the height-dimensions of the dish). That surface would garanteedly be parabolic, I presume.For the calculation you need hight of the dish, depth of deepest point, and location of deepest point (all measured at working area).So does Parabola2 program (forget the program for focalpoint calculation; it it highly inprecise due to assumption of bottom at vertex). <img src="https://www.satellites.co.uk/styles/default/xenforo/smilies/smile.png"&nbsp; class="smilie" loading="lazy" alt=":)" title="Smile&nbsp; &nbsp; :)" data-shortname=":)" />Or, alternatively: measure distances of top to bottom of the dish (=height of the dish), bottom to deepest point (measured AT the dish!), and deepest point to top of the dish. (Thus the measurement of the fictitional triangle of the dish: Top-Bottom-DeepestPoint; all measured at working area of course.)From that you can also calculate offset angle. <img src="https://www.satellites.co.uk/styles/default/xenforo/smilies/smile.png"&nbsp; class="smilie" loading="lazy" alt=":)" title="Smile&nbsp; &nbsp; :)" data-shortname=":)" /><img src="https://www.satellites.co.uk/styles/default/xenforo/smilies/smile.png"&nbsp; class="smilie" loading="lazy" alt=":)" title="Smile&nbsp; &nbsp; :)" data-shortname=":)" />Greetz,A33</blockquote>

[QUOTE="a33, post: 1027389, member: 332642"] Well, Rima, I'm no expert on triax dishes, but is it possible to do a string test on [I]the working area[/I] of the TD110? Maybe the rim of the dish, though perfectly flat at the front of the dish, has different 'heights' to the working area of the dish? I've seen a picture of such a dish once, and it would explain a lot. For that reason I would prefer the calculation of offset angle by measuring the deepest point of the dish (compared to the height-dimensions of the dish). That surface would garanteedly be parabolic, I presume. For the calculation you need hight of the dish, depth of deepest point, and location of deepest point (all measured at working area). So does Parabola2 program (forget the program for focalpoint calculation; it it highly inprecise due to assumption of bottom at vertex). :) Or, alternatively: measure distances of top to bottom of the dish (=height of the dish), bottom to deepest point (measured AT the dish!), and deepest point to top of the dish. (Thus the measurement of the fictitional triangle of the dish: Top-Bottom-DeepestPoint; all measured at working area of course.) From that you can also calculate offset angle. :):) Greetz, A33 [/QUOTE]

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