"spiney" <sparkistuf@hotmail.co.uk> wrote in message
news:1133612185.052831.52420@o13g2000cwo.googlegroups.com...
WARNING Adrian is useless (but I support his right to post).
Satellite "antenna".
A yagi design is not viable for sat Ku band, since at that frequency
the elements are too small, and anyway you won't get enough gain, and
it would need to be impractically long, and then in any case you
couldn't have a 1Ghz bandwidth!
The LX200 is a "dielectric antenna", as commonly used in microwave
system. From reports, it isn't as good as a standard lnb with a 43cm
minidish, but is usable for Sky.
Does anyone know if this is simply a sausage shaped lump of plastic that's
solid all the way through, or is there more to it? Why is it tapered into a
teardrop shape at the end that points to the satellite? What shape is the
dielectric inside the tube, could it be conical pointing at the satellite,
conical pointing into the LNB, or would there be more than one seperate
section of dielectric? What sort of material is the dielectric? Does anyone
know any links to information about dielectric antennas for microwave? Would
it be possible to make my own dielectric rod antenna out of a suitably large
chunk of plastic, and just tape it to the front of an LNB, or does it need a
very precise shape and special materials?