[MLB-WIRELESS] Wireless connection -1200m apart

[Jamie Moir]

On Wed, 18 Feb 2004, Winder wrote:

>  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?

Go read some specs and answer your own question.

If you buy shoddy G gear, that has worse sensitivity than good B gear, and
you have a poor signal, then your link will be slower than G than with B
gear.

*Yippeee*

till

>   -----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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