Alt-BEAM Archive
Message #07346
To: beam@sgiblab.sgi.com
From: Ed Spike spike@engmail.uwaterloo.ca
Date: Wed, 03 Nov 1999 11:58:33 -0500
Subject: [alt-beam] Re: directional antenna?
A few questions!
What frequency?
What beam width for half-power of the signal?
What baud rate (to determine bandwidth and phase distortion)?
Omni directional is in all directions. It could be omni directional in
one 2D plane (ie: parallel to the earth).
Uni directional is in one direction.
Some primary thoughts:
1. An array of dipoles over a flat ground plane.
2. An array of three or four element yagis over a flat ground plane.
3. A right angle corner reflector with a dipole feed.
4. A right angle corner reflector with a multi-element yagi.
5. A array of corner reflectors.
6. A micro-strip patch antenna array.
73,33
Bob Shannon wrote:
>
> "Van Zoelen, Bram AA SSI-TSEA-352" wrote:
>
> > An unidirectional antenna would be something like a wire straight up.
> > Just think about a car antenna. That's a uni-directional antenna.
>
> Ahh, thats an omnidirectional antenna.
>
> For some good ideas on radio direction finding, I reccomend the book 'Hidden
> Transmitter Hunting Made Easy', published by the American Radio Relay League.
> The show a fairlt simple dopper based direction finding system that is very
> good, but its a little complex. This book also covers simpler systems that are
> more BEAM-like.
7347 Wed, 3 Nov 1999 12:25:29 -0500 [alt-beam] FLED Cover-up ( FYI) "Ed Jones Jr."
While working on a FLED triggered carbot , I found I had no more
heat-shrink tubing in my misc. supply box . Since it was halloween & my
girlfriend dressed up as a witch complete with black fingernails , I
wondered if her fingernail polish would work instead . I am happy to report
it works great & at .29 cents , a bottle should last a long time . I have
since tried several other colors , although some require 2 or 3 coats , all
have shielded the FLED from light sources . So go cheap & and add some
color to your fleds .
Ed Jones
sargon@gte.net
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