[MLB-WIRELESS] Wireless connection -1200m apart

[Ryan Abbenhuys]

Never EVER mention 108mbit mode around here!!!!!
grrrrrrrrrr

----- Original Message ----- 
From: Winder
To: melbwireless at wireless.org.au
Sent: Wednesday, February 18, 2004 8:05 PM
Subject: RE: [MLB-WIRELESS] Wireless connection -1200m apart


It would be interesting to have someone such as yourself do some testing on
G cards with maybe a cheap home made cantenna and see what signal to noise
ratio you get, and if you get a high speed connection or not. If the
cantennas don't give you a high speed connection, then you could spend money
on some Hills antennas and compare the new signal / noise ratio and if that
improves the llink enough to allow the higher speeds that G offers.

I'd even be interested in seeing the 108 meg modes that some cards offer
will work too. If I ever get a G card, I think I'd get a 108 meg capable
one.

 One question about G to everyone, will a G card swapping form B to G mode
provide better or worse performance than say just B mode itself?

Regards,
g at z.

-----Original Message-----
From: owner-melbwireless at wireless.org.au
[mailto:owner-melbwireless at wireless.org.au]On Behalf Of Michael Borthwick
Sent: Wednesday, 18 February 2004 7:19 PM
To: melbwireless at wireless.org.au
Subject: Re: [MLB-WIRELESS] Wireless connection -1200m apart



On 18/02/2004, at 4:45 PM, Phil Mawson wrote:




I had seent he Vagi directional antennas by Hills. But it only has a 15.6dBi
rating. As I said before, I am new to wireless, but I gather that a 25dBi
rating is better, and the parabolic grid antenna is only another $10. Or
would the Vagi antenna be better because it is more directional therefore a
higher signal strength?


No. The Vagi has 10dBi *less* signal strength than the parabolic but what
you're not appreciating (and you are in good company) is that once you have
*enough* signal at each end (technically a high enough signal to noise
ratio) for the two radios to connect at their highest data rate then any
additional signal strength provides no increase in speed. Therefore it is
not automatically "better" as you write above - unless you decide to swing
one of them around and join us in the Melbourne Wireless network.

In fact over that distance you might get away with building any of a number
of very cheap home made antennas such as helicals, cantennas, antcaps,
corner reflectors which might offer you around 10dBi gain which could be
plenty for your application.

You can work what you need by calculating what is called the "link budget"
for your link. This is straightforward and will help you to understand what
is going on.

Regards,

Mike


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