difference between 5.8 and 2.4 antennas

[simcor23]

Was wondering if anybody knew the difference between a 5.8 and 2.4 antenna.
The reason being without thinking I setup a WAR AP with a WAR client in B mode 2.5 km's away in 2.4ghz mode. The AP is a 5.8ghz hyperlink 17 dbi sector and the client uses a 5.8ghz 21 dbi mini grid from pacwireless and the link is awesome great throughtput????

How is that?

I have made antennas out of coffe cans, and tore apart quite a few antennas just to find out it is basically a piece of copper and some insulation. What makes a 2.4ghz antenna 2.4 and a 5.8ghz antenna 5.8???

Any input would be greatly appreciated.

Thanks

[titan_wireless]

Well your link is not very far. It does not supprise me that it works. The only diffrence is the radiating element is smaller at 5.8 then 2.4.

[simcor23]

Thanks,


Maybe out of curiosity I will try my 11km link and see what happens.

[tog]

In my very limited experience with messing with the incorrect antenna for the frequency I'm set to, I would say the gain of the antenna very much affects its ability to pass the frequency it isn't tuned for through it.

Using the wrong antenna most certainly does knock lots and lots of dB off your signal, but after the dB is lost if you still have enough dB left for a good link, then you will probably perform all right, but with possibly some additional distortion and higher BER than you would normally get out of the signal strength you're at.

[simcor23]

My 2.5km link is rssi -58dbm ping consitent at under 3ms throughput 2800KB/s minimum, cloaking x4 over the air reads 13.5 actual internet speeds are exactly the same on client end as if i was plugged into switch. Uptime 26 days and running smooth?


Weird!!!

[luka]

I have 2.5km link with two 5.8 antennas but on 5.3 ghz. Rssi is -48, throughput ok, but seeing ping/availabity statistics I see there some packet loss of 0,5-2%, compared to 0-0.02% put on nearby link. I think this is exactly due to antennas and will check it after replace antennas with designed ones.
Beside gain, there are other elements like vswr which fluctuates much for non-designed frequencies. Weather conditions should be accounted too. It is very interesting how weather can affect antennas and signal and this relation can be different for different antenna designs. For instance, yagis are much more water sensitive 2.4 antenna and only 0.5mm of condesation on basic antenna element can make you link dead.