Hyperlink 12 dB omni antenna

[mo]

Do any of you have any comments about this antenna? Planning on purchasing soon :lol:

Thanks :wink:

[Skaught]

We have some 15dbi hyperlinks. 3 of our 5 hub sites use them. The other sites use sectors.

If you can use sectors, they are better no doubt. Usually we will install an omni and then when we have more clients we break it up into sectors.

I would not bother with the 12dbi. The 15s work ok for us. Noise is an issue at one site from time to time. One issue with the 15s is if your tower is very tall you will get shadowing. Our towers are only 80 feet tall or less so I have not had any shadow issues.

Back when I did commercial and had a site that was 600 feet tall, we only used sectors.

[mo]

How can that be? Are they defying the laws of physics :shock:

[bradg]

How can that be? Are they defying the laws of physics :shock:

Basic antenna "gain" theory.

Basically, when referring to antenna's "gain", it refers to it's signal strength (at a fixed distance) as compared to an "isotropic radiator" - one that radiates perfectly and evenly in a sphere around it.

Omnidirectional antenna's with "gain" over zero acheive this by "squashing" the radiation pattern. After all, usually there isn't much call for signal to go straight up, right?

So, the higher the "gain", the more squashed (or modified) the radiation pattern becomes. Think of it like you were squashing a perfectly round ball of dough into a pancake. The ball no longer "reaches" up or down, but "reaches" much, much further out radially than it's original diameter.

So, when people refer to an area being "shadowed", that means that the antenna's radiation pattern is such that people near the antenna are effectively "under" the antenna's radiation pattern - under the "pancake".

All antennas with "gain" work in a similar manner, but have their radiation patterns focused or modified to radiate in a non-spherical pattern.

Hope this helps.


Brad