Thanks Tref and Midge,
>> and the centre of the cord ceases to move much, that is an antinodes.
Ah, nodes and antinodes. Had forgotten about them, but then it is several
decades since school physics ;-)
My WAP does have two antennae about 7" apart and on a line roughly
perpendicular to both the main client machines which are on directly
opposite sides of the WAP. Which disallows Midge's suggestion of a
shield/reflector.
I can understand that the wave forms can create hot and blind spots, but
what factors, especially local ones that I can do something about, make the
signal vary so much?
And yes we have spend months experimenting with siting the WAP.
DR
--
David Rayne
Medical Web Services Ltd
www.mwsuk.co.uk
Original message from Adrian Midgley <> on 15 October 2004 23:41:
> On Friday 15 October 2004 22:46, Trefor Roscoe wrote:
>
>> Midge tried to but could not be understood :-)
>>
>> The signal is of course a wave and there will be harmonics in it.
>> Some of these will sum and others cancel out.
>
> Strictly, not harmonics.
> In Physics at school we took hold of a long cord and waved an end of
> it up and down, at a particular frequency you get a doubling, and the
> centre of the cord ceases to move much, that is an antinodes.
>
> The classic experiment with two slits and a diffraction pattern has
> something to do with the same sort of thing.
>
> The wavelength of the radio particles is pretty short, and the two
> antennas on a typical router eg Linksys WRT54G are a suitable
> distance apart that hopefully you are at a node distance from one, if
> you are at an antinode form the other.
>
> But what with signal paths and reflections and refraction around
> objects, it is not surprising if destructive and constructive
> interference produce dips and peaks in signal strength in various odd
> spots.
>
> Changing the radiation pattern from one of the antennas will commonly
> alter that... and just boosting the strength may suffice to get
> contact.
>
> On the receiving antenna, blocking out (attenuating) the half of the
> world away from your transmitter's direction also may allow reception
> to work.
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