DIYbanter - View Single Post - OT

On Tuesday, in article
"Timothy Murphy" wrote:

Brian {Hamilton Kelly} wrote:

You are apparently a mathematician; can you not understand the concept of
the dish being a *part* of a parabola, rather than its centre?

For "centre" read "focus" ?

NO! The LNB *is* at the focus of the parabaloid of which the dish you
see is but a part. The diagram of "how an offset antenna works" in the
http://www.lindenreport.com/tech/satworks.html mentioned elsewhere in
the thread shows this quite clearly.

(Although for operation within the UK, I'd have preferred it if the
diagram had been reflected about a line going SW--NE on the page, such
that the "incoming rays" from the satellite were still pointing upwards
and to the right, but at a more realistic elevation angle. That diagram
looks like a set-up for UAE or thereabouts [which ties in with the
article originally having been published in a magazine circulated in that
part of the world].)

--
Brian {Hamilton Kelly}
"I don't think you're in the top class when it comes to thinking
- I suspect I could wade through the depths of your mind and not
wet my ankles." Peter Thomas, in news:uk.telecom 24-Jul-2005