[MLB-WIRELESS] Wireless Network Project
Ratbaggy
wireless at smithsgully.net
Fri Jan 16 11:12:39 EST 2009
Hi Steve,
I may have a solution for you using Jason's Minitar contact.
Three years ago, I helped a mate set up a sytem in an identical scenario
to get some internet up to his parents place 500 m away. We used the
old Minitar 11B devices mounted in Jaycar sealed polycarbonate
enclosures (HB6218 etc.). The great thing with this setup is you drill
a hole in the box, mount a gland (Jaycar HP0732 etc.) and poke the
unit's own antenna down through the gland to be used as the driven
element in a trough reflector. Another smaller gland is used for the
cat5 cable (Jaycar HP0724 etc.)
There is some cutting and 2 bends of a sheet of aluminium which mounts
on the back of the box to form the trough reflector. We used a TV mast
bracket sandwiching the aluminium plate on the back of the box to
support the aluminium reflector and mount the box to the TV hockey
stick. (Brackets from Alvin electronics "FWM" flush wall mount, on this
page FWM
<http://www.alvin.com.au/index.cfm?siteaction=catalog&mcat=10&cat=47&sr=21>.
Bitek in West Heidelberg also have similar brackets)
This setup yields about 8 dB of gain at each end of your link WITHOUT
buying an antenna or any pigtails or any losses associated with
connectors or feeders.
We cut the DC plug and a few cm of cable off the power pack and used the
spare pairs in the cat5 cable to power the unit. The old Minitars had
an internal switchmode power supply which tolerated quite a wide input
range so the DC losses in our 10 m run of cat5 weren't a problem. You
may well get away with it with the new units too, I see they run off 9
Volts.
The costs:
2 AP's @ $35 = $70
2 Boxes @ $17 = $34
2 FWM's @ $7 = $14
Bag small Glands @ $5
Bag larger Glands @ $5
Scrap Aluminium sheet $ 0
Assorted Hardware
Total Cost $128.... Way under budget!
If you want to give the design a try I can go take some pictures of the
units (which are still in situ and working after 3 years!) and supply
you with the dimensions of the aluminium sheet.
Regards
Dave
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