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<blockquote data-quote="Simba27" data-source="post: 60951" data-attributes="member: 182734">As a newb here, I don't wish to dispute your expert opinion Rolfw. But I have some vague memories of A-level physics which I'd like to enter into the discussion.<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=":)" />When a wave meets a hole smaller than the wavelength, doesn't it get &quot;diffracted&quot;, ie. spread out? And with multiple holes, IIRC, this leads to interference patterns.Surely for the purposes of satellite reception it's better to reflect the wave in the direction of the LNB than to diffract it?I can see that the precise shape of the dish is very important to direct the signal into the LNB. My rough estimate suggests that, on this size of dish, the surface must be within 2 degrees of the correct angle. I think that's achieveable by simply sanding the filler flush to the metal surrounding it.I'm actually going to try this in a very scientific way and measure the gain or loss (if any). It won't be for a good few weeks though because I have a long list of more important things to do. <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite8" alt=":D" title="Big Grin&nbsp; &nbsp; :D" loading="lazy" data-shortname=":D" />BTW. Am I posting this nonsense in the right area? I've noticed that most of the posts in the alcove are non-satellite related.Phil.</blockquote>

[QUOTE="Simba27, post: 60951, member: 182734"] As a newb here, I don't wish to dispute your expert opinion Rolfw. But I have some vague memories of A-level physics which I'd like to enter into the discussion.:) When a wave meets a hole smaller than the wavelength, doesn't it get "diffracted", ie. spread out? And with multiple holes, IIRC, this leads to interference patterns. Surely for the purposes of satellite reception it's better to reflect the wave in the direction of the LNB than to diffract it? I can see that the precise shape of the dish is very important to direct the signal into the LNB. My rough estimate suggests that, on this size of dish, the surface must be within 2 degrees of the correct angle. I think that's achieveable by simply sanding the filler flush to the metal surrounding it. I'm actually going to try this in a very scientific way and measure the gain or loss (if any). It won't be for a good few weeks though because I have a long list of more important things to do. :D BTW. Am I posting this nonsense in the right area? I've noticed that most of the posts in the alcove are non-satellite related. Phil. [/QUOTE]

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