[MLB-WIRELESS] Directionality...

Tony Langdon, VK3JED vk3jed at optushome.com.au
Mon Aug 7 14:26:27 EST 2006

At 01:21 PM 8/7/2006, Gustaf Bjorksten wrote:

>The problem with directional antennas is that you have to be 
>pointing it in the "right" direction to get an indication of the 
>direction of the source. Antenna arrays and loop antennas give you 
>an indication of direction without you having to move, or (more 
>importantly in my application) /despite/ your heading.
>Hence further research being required :)

True.  However, there is a simple solution to that, which requires a 
high powered AP at one end.  Feed omni with high powered AP (or 
AP/amp combo), set it up so the power is at the legal limit.  Align 
the directional antenna at the distant end of the link.  Once this is 
done, you can replace the initial omni with the desired antenna and 
point back in the opposite direction. :)

Also, this is a reason I suggested UHF CB for initial alignment.  The 
much higher legal power of UHF CB will allow the use of an omni on 
that band at one end, and a directional at the other.  Once you have 
a rough (within 5-10 degrees), you should be able to get a viable 
WiFi signal if the path is good, and then fine tune the alignment of 
the antennas...  And I'll call it quits, if I can't get within 5 
degrees using a map and reasonable. :-)

The problem's not that difficult to solve, you only need to get with 
5 degrees (often 10 will do) on the initial alignment.  We're not 
pointing lasers here, or even 10 GHz dishes...

73 de VK3JED

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