"Richard Clark" wrote in message
...
On Tue, 22 Mar 2005 02:37:15 GMT, "Dale Parfitt"
wrote:

I have worked with parabolas for years- the current dish is a 14' w/ 0.36
F/D and illuminated with a scalar feed. A dipole is perhaps one of the
worst
feeds for a parabola. If you're going to put the surface up why not take
full advantage of it? It takes little if any additional work to properly
illuminate it.

Hi Dale,

Well, I described how to build the reflector, you can describe how to
build the horn. Myself, I think that at 900MHz that is where the
trouble is going to start as the horn will almost certainly shadow the
reflector that already gives him 10dB gain.

Now if Nigel is trying to stretch Wi-Fi into Wi-Max, then such an
investment may be opportune.

73's
Richard Clark, KB7QHC
Hi Richard,
Depending on surface size, that may be correct. An offset dish and an 0.7F/D
horn would avoid that problem. Without doing the math, the now defunct- and
available fro free, Primestar 1M offset dishes may be an excellent solution.
Then again, if he only needs 10dB, a small loop yagi could serve with a lot
less surface area.

Dale W4OP