Big Antenna Projects - Multi MILE Range

There were some posts a while back discussing ways of increasing range
and throughput in your wireless connections. I put together some
construction guides at:

http://www.ab9il.net/wifi1.html


For popular USB wireless adapters there are also external antenna mods
that work great.


Regards,
Phil AB9IL

On Sep 5, 1:17*pm, Jeff Liebermann <je...@cruzio.com> wrote:
> On Fri, 5 Sep 2008 08:03:00 -0700 (PDT), ab9il.worldw...@gmail.com
> wrote:
>
> >There were some posts a while back discussing ways of increasing range
> >and throughput in your wireless connections. *I put together *some
> >construction guides at:
> >http://www.ab9il.net/wifi1.html
>
> Nice, but...
> <http://www.ab9il.net/wifi3.html>
> It seems your helical feed is Right-Hand circularly polarized. *When
> bounced off the dish, it becomes Left-Hand circular plarization. *As
> long as that's intentional, there's no problem. *However, you should
> mention that in the article as someone is sure to get it backwards.
> Convention for terrestial links and commerical helical antennas is
> RHCP, but that's not a hard and fast rule.
>
> Suggestion... I've tried various antennas made from copper tape
> (usually ribbon used for stained glass making) and found that they
> move around too much. *Fortunately that's not a problem for a helical
> antenna as its extremely wide bandwidth gives considerable lattitude
> in construction practices. *For helixes, I find it easier to have a
> machine shop gouge a grove into the pipe. *That allows me to use
> common #12AWG round copper wire, which is cheaper and easier to work
> with. *I had about 40ft of 1" dia ABS and white PVC pipe grooved for
> the purpose a few years ago for about $50. *One 10ft section is enough
> to build about 5 antennas. *I had them cut for various turn spacing so
> I could experiment. *However, I made them all RHCP, which kinda ruined
> it for testing reflector antennas. *
>
> --
> Jeff Liebermann * * je...@cruzio.com
> 150 Felker St #D * *http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann * * AE6KS * *831-336-2558

Jeff, If I wanted to have a piece of PVC pipe machined for a helical
antenna what would I need to tell the machinist.

Jimmie

> > <http://www.ab9il.net/wifi3.html>
> > It seems your helical feed is Right-Hand circularly polarized. *When
> > bounced off the dish, it becomes Left-Hand circular plarization. *As
> > long as that's intentional, there's no problem.

Guys, thanks for the comments. It helps me focus on what matters to
antenna builders out there.

I've added a note in the construction guide regarding the
polarization. In a nutshell, if you are using circular polarization
on both ends, they need to match - with consideration for the reversal
in a parabolic reflector. If the parabolic is linking with an AP with
linear polarization, it isn't an issue. A ten turn helical (or a
short helical on small TV dish) more than makes up for any
mismatches. Okay on grooving the PVC. I'll have to give that a try on
my next project; the copper tape is fine for indoor antennas (with
some clearcoat spray). I envision marking a length of PVC and
grooving it with a dremel tool - should result in a helical tough
enough for outdoor use!

Regards,
Phil AB9IL

http://www.ab9il.net/