Posted by Jean-2 on
URL: https://www.es-forum.com/Re-shielding-tp1540370p1540388.html

thanks for the answer. I'm still trying to figure out more about
this question. Interferences, signal recombination, ugh. It's messy
physics. It might be interference between two masts, cause I'm
really facing the masts without anything in between. And there are
big variations just moving the meter 30 cm, and pointing in the same
direction.

jean.

--- In [hidden email], "Ian Kemp" <ianandsue.kemp@u...> wrote:
>
> The theory of interference patterns is that one could get down to a
complete
> zero signal at the "antinode" and double the original signal at
a "node".
> However a meter may not be able to measure a location that
accurately. And
> I am only guessing that it is a true interference pattern; local
variations
> can be caused by other effects e.g. reflection, partial blockage,
trees
> etc., as others correctly said previously.
>
> Ian
>
>  
>
> _____  
>
> From: [hidden email] [mailto:[hidden email]] On
Behalf Of jean
> Sent: 19 January 2006 19:52
> To: [hidden email]
> Subject: [eSens] Re: shielding
>
>  
>
> --- In [hidden email], "Ian Kemp" <ianandsue.kemp@u...>
wrote:
>
> > Incidentally, when two beams overlap, the "nodes" referred to by
> Charles and Shivani can be an "interference pattern", with
alternating high
> and
> low intensities a short distance apart, caused by transverse waves
at
> different points in their cycle either reinforcing each other or
cancelling
> each other out.
> >
> > Ian
>
>
> Yes, depending of the exact distance, and different signal from
each
> mast, ... sinusoidal variation, ... Although I'm not sure that in
> the average if I keep the meter at the same point a while, 20 uW of
> difference is a lot. I get something like 15uW in one points and
35
> uW 30cm apart. Anybody has the exact math theory ? I don't have
> anything between the window and the mast it's too high for the
trees.
>
> jean.
>
>
>
>
>
>