Low Cost 802.11A Directional Antenna using obsolete PrimeStar Dish

Our workgroup had been seeking a low cost temporary solution for a point-to-point link to an offsite facility. We needed greater than 10Mbps throughput and thought 802.11a wireless might offer some promise.

At the present moment (June 2002) no manufacturers offer low-cost devices with detactable antennae. This significantly limits range of 802.11a to around 300 Meters under the best conditions. Directional antenna are needed to focus the send/receive energy at further distance.

Inspired by the work of Rob Frohne and his Primestar Wireless Antenna Page - http://www.wwc.edu/~frohro/Airport/Primestar/Primestar.html . I decided the solution was to integrate the low-cost Access Point, directly into an obsolete PrimeStar TV Dish.

After a little experimentation and engineering (the feed horn is a particularly important component). I found that simple modification of a US standard aluminum soda can would work. I obviously have a few mounting and water-proofing details the work-out.

Much to my shock, It Worked!!! I was able to get to the end of my test range easily (~1000ft), and my latop was registering 60% signal strength and 24Mbps connectivity. Now onto the actual installation...

I guess that the side-to-front gain is around 9-10db. The large area of the Primestar dish seemed to help pick-up the much lower energy laptop card well (I had tried previously with a Dish Network dish).

A rough design of the feed horn,
a sode can is 2.5inches, a bit
too big.

Cut top off can, cut
antenna hole 0.6" from

Original PrimeStar feed horn.
in final install I will modify
it and use its mounting.

For this test, I wrapped the
the unit in foil to eliminate
its effect.

Netgear HE102 ready to install.
OBTW, the foil also helps one
ground the can, which is needed.

Installed as close as possible to
original location

OK, packing tape will do the
job for now... It works for me.

Fully outfitted PrimeStar Dish
ready for testing...

My test range, I am limited to
around 1000ft.

June 29, 2002 Dean Eckstrom