Wi fi antenna

[Deigh]

I've been studying wi-fi antenna designs to try and improve my knowledge and at the same time build an efficient system. I can now pick up free Spark wi fi from a telephone kiosk which is not only approx 500metres away but not even strictly in line-of-site. I feel I can improve on this but need knowledge and can't discover where to find the real information about the practical side of antenna and theory.

for instance I need to know how the black flexible rod aerial is constructed and why it is usually black.

U tube is full of build-your-own rigs and has been a valuable source of information, Wikipedia has also been tremendous but I need to know more, can anyone point me in the correct direction? (no pun intended!).
Deigh

 

[davenn]

I can now pick up free Spark wi fi from a telephone kiosk which is not only approx 500metres away but not even strictly in line-of-site.

500m is long haul for WiFi, specially for a non-line of sight path

some respectable gain would be needed to ensure you didn't get continuous drop-out

down the bottom of this page on my www site you will see a 2.4 GHz Yagi I use for various 2 GHz activities

http://www.sydneystormcity.com/microwave.htm

one like/similar to that would be ideal

I need to know how the black flexible rod aerial is constructed

it will, most likely, just have a wire whip inside it

and why it is usually black.

colour is irrelevant .... most antennas happen to be either black or white


Dave

 

[Deigh]

Thanks for that breakdown of the antenna makeup. Have you any idea on the value of the shape differences? some are straight, others have tapered areas and yet others have bands around them. The one I am using is straight with a slight taper 400 long and is probably a "D Link".
Your calculations leave me to shame, I'm just a twist it together and hope for the best experimenter.

This is it, couldn't be more amateur!
I may be exaggerating about the 500metres, I have only guessed it, and will probably come down to 400. But I can use Spark all day without any dropout except when they deliberately shut it down, (probably to deter permanent users). Most of the time I am using wi-fi from the local library which is only 100m away, or from my phone Spark account.
It hangs vertically on the curtain behind the computer, suspended by a clothes peg.
Deigh