[MLB-WIRELESS] Hong Kong Ebay antennas

[Rob]

Hello Gaz,

Dave is right, the whips you have are tuned for 5.4 GHz....

They are not Dipoles though, Dipoles are center fed and have equal size
radiators each side of the feed point...

Dipoles have a 0 DB gain compared to an Isotropic antenna, what you have is
most likely a 1/4 wave stub feeding a 5/8 ( or multiple ) whip through a
phasing coil ( near the center )

The fact that they are not connected electrically at the connector means
they are capacitively coupled, quite a good thing when done properly,

As Dave suggested, sweep them and tune them for 2.4 GHz 

Cheers,

Rob.



-----Original Message-----
From: melbwireless-bounces at wireless.org.au
[mailto:melbwireless-bounces at wireless.org.au] On Behalf Of Ratbaggy
Sent: Tuesday, 8 January 2008 11:38 PM
To: melbwireless at wireless.org.au
Subject: Re: [MLB-WIRELESS] Hong Kong Ebay antennas

Hi g at z,

Judging from the length of the dipoles (the straight sections of wire) 
and comparing to the size of the linksys antenna, I'd suggest the 
antennas are tuned for 5.8 GHz not 2.4.  If you bring them to the next 
meeting we can sweep them and see which frequency they absorb the most 
energy.

...and with only 2 dipoles, the gain at 5.8 would be more like 5 dBi

Dave.


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