Can an old DirecTV Dish seriously be used as wifi antenna?

I have heard that some folks out there have SUPPOSEDLY gotten good
reception on wifi (802.11g) by using an old DirecTV satellite dish to
amplify the signal.

Have any of you actually done this, or known anyone who has done it? I
don't mean read about it, but actually seen it work, in person.

I got an old DirecTV dish for $1 at a yard sale last week, and have
been wondering what other things I might need if this rumor is true.
Thanks!

On 19 Aug 2006 18:03:36 -0700, "slugbug" <fuzzhead72@yahoo.com> wrote:

>I have heard that some folks out there have SUPPOSEDLY gotten good
>reception on wifi (802.11g) by using an old DirecTV satellite dish to
>amplify the signal.
>
>Have any of you actually done this, or known anyone who has done it? I
>don't mean read about it, but actually seen it work, in person.

Well, I haven't due to lack of time, and because I can buy a
commerical dish with approximately the same gain for about $40.

>I got an old DirecTV dish for $1 at a yard sale last week, and have
>been wondering what other things I might need if this rumor is true.

The problem is that even if the feed illuminates the dish perfectly,
the maximum gain from a 0.6meter dish antenna is about:
gain = 9.87 * Dia^2 / wavelength^2 * (feed efficiency)
gain = 9.87 * 600mm^2 / 125mm^2 * 0.4
gain = 91
dBi = 10 log(91) = 19.5dBi
The 40% efficiency (that's the 0.4) is probably optimistic. Your gain
will probably be less. If you want do something useful, methinks
you'll need a bigger dish.

Here's one that's nicely done:
| http://www.weijand.nl/wifi/

Here's one that sorta maybe kinda works, even though his biquad feed
construction is wrong.
| http://www.engadget.com/2005/11/15/h...-dish-antenna/

Note the lack of gain measurements.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 jeffl@comix.santa-cruz.ca.us
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

Here is a link to one.

http://www.qsl.net/ki7cx/wgfeed.htm

Tony


"slugbug" <fuzzhead72@yahoo.com> wrote in message
news:1156035816.235532.237940@i42g2000cwa.googlegr oups.com...
>I have heard that some folks out there have SUPPOSEDLY gotten good
> reception on wifi (802.11g) by using an old DirecTV satellite dish to
> amplify the signal.
>
> Have any of you actually done this, or known anyone who has done it? I
> don't mean read about it, but actually seen it work, in person.
>
> I got an old DirecTV dish for $1 at a yard sale last week, and have
> been wondering what other things I might need if this rumor is true.
> Thanks!
>