Log in
Register
Menu
Log in
Register
Home
What's new
Latest activity
Authors
Forums
New posts
Search forums
What's new
New posts
Latest activity
Members
Current visitors
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Satellite TV receivers & systems support forums
Fringe Reception General
Anyone tried to make BIG dish at home?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="a33" data-source="post: 1096538" data-attributes="member: 332642"><p>Timing/distancing ("in phase") is one thing, another thing (I think even more important) is the feedhorn I guess.</p><p>A feedhorn expects an 'equal' field of signal, so to say, preferably with the highest density in the center.</p><p>So if you create more parabolic surface (by combining several offset dishes), but with holes in it; then from the holes you receive noise. (Unless you have a feedhorn with a shape, that matches the exact illumination by the parabolas.)</p><p>Adding a secondary mirror (cassegrain or gregorian) doesn't alter that.</p><p></p><p>So the effect is that you get more signal, AND more noise. So the S/N ratio result will likely be about the same as with just one offset dish, or maybe even worse.</p><p></p><p>When you want a bigger dish surface: Buy/make a bigger dish! All other solutions are troublesome, or maybe even worse....</p><p></p><p>Greetz,</p><p>A33</p></blockquote><p></p>
[QUOTE="a33, post: 1096538, member: 332642"] Timing/distancing ("in phase") is one thing, another thing (I think even more important) is the feedhorn I guess. A feedhorn expects an 'equal' field of signal, so to say, preferably with the highest density in the center. So if you create more parabolic surface (by combining several offset dishes), but with holes in it; then from the holes you receive noise. (Unless you have a feedhorn with a shape, that matches the exact illumination by the parabolas.) Adding a secondary mirror (cassegrain or gregorian) doesn't alter that. So the effect is that you get more signal, AND more noise. So the S/N ratio result will likely be about the same as with just one offset dish, or maybe even worse. When you want a bigger dish surface: Buy/make a bigger dish! All other solutions are troublesome, or maybe even worse.... Greetz, A33 [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Satellite TV receivers & systems support forums
Fringe Reception General
Anyone tried to make BIG dish at home?
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top