Info on an 800m link with 2 x DLink AP-900+

[Haydn Lowe]

Hi there,

I originally planned to write to ask for help - but have since figured it out, 
and thought I would present my experiences...

I've finally managed to get an 800 m link up and running at 5.5 Mbps using two 
DLink AP900+ units.
I have used two stand alone bi-quad antennas as described by Trevor Marshall, 
and other associated web sites. Sealed in good old Woolworths tupperware 
specials (complete with rubber seals!)

Initially, all I could get was a 500Kbs link, which dropped out frequently.
The error rate was nearly 25%, and I had Line of sight, but simply couldn't 
figure out why. I've had many different iterations all with about the same 
results. On the weekend I finally figuring it out!

It turns out that the AP900 units have a built in second antenna, which I guess 
isn't all that surprising, but wasn't well documented AND that there is a 
hidden configuration page http://<ap900-URL>/weca.htm which allows you to 
control the antenna configuration, as well as a few other things...

I disabled the internal antenna - and set it to use only the right antenna 
(this is the external one). And this has fixed my problems!

I don't know if it is simply diversity, or a combination problem with the fact 
I am running the far unit in repeater mode, but I do know that tweaking with 
the antenna settings has fixed my problems. So I thought I'd share the info...

Does anyone know what sort of link speeds I should be able to get to work over 
an 800 m  stretch? Is 5.5 about right, or should I be trying to get it faster?

Any thoughts on all this are welcome!

Cheers
Haydn