From: Kevin McMurtrie
Newsgroups: rec.radio.amateur.homebrew,sci.electronics.design,sci.electronics.basics
Subject: Re: Detect direction of radio transmitter??
References: <1783abaf.0211031748.f234799@posting.google.com>
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Date: Mon, 04 Nov 2002 09:08:56 GMT
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In article <1783abaf.0211031748.f234799@posting.google.com>,
holysmokes99@hotmail.com (Marcus) wrote:
>I am a total newbie to anything to do with electronics, radio waves,
>etc, but was just wondering something. If I placed some kind of radio
>receiver at the end of a narrow tube that was shielded againsst radio
>waves except at the other end (the opening), and had a radio
>transmitting source a few hundred feet away, would I be able to
>determine the direction of the source of the radio waves by turning
>the 360 degrees in all directions, with the direction of the strongest
>reception being the direction of the source?
>
>I have really no idea the nature of radio wave bouncing, etc. Just
>curious....
>
>Thanks,
>Marcus
It would only work for GHz frequencies. Openings bend waves. The lower
the frequency and the smaller the opening, the more it's bent. This
happens for pond ripples, sound, RF, and even light (CD rainbows are the
obvious example).
Take a look at how Yagi TV antennas are built. Only signals going in
the proper direction will be received. Everything else cancels and is
reflected off grounded poles.
Lower frequencies require multiple antennas and phase detection, unless
you want a monster Yagi aerial.