A detailed analysis of the VE3DO Loop is on my web site:
http://www.ok1rr.com/index.php/antennas/8-the-ve3do-receiving-loop
A NEC file for further investigation is available via email upon request.
That's a good analysis Martin.
None of these antennas are any different than any others in function, and
there is virtually no difference in noise or directivity. They are all, if
properly built, the same.
While they all behave like two short verticals, they will all work a little
worse than two pure short verticals
because the transmission lines between the verticals (the horizontal wires)
radiate.
There are an infinite number of shape changes, and several feed method
changes, that can be used. But they all, in the end, work about the same
when properly built. Two small phased verticals would just be better because
feedline radiation, which is the horizontal space the wire occupies, is
eliminated and contained inside a shielded cable.
They can be triangles, U's, rectangles, flags, or anything else with a
horizontal length that is long compared to vertical height of the ends. They
can use the ground as a return (which makes them dependent on good earthing
rods for connections) like an EWE or the VE3DO loop (which is exactly like a
EWE with displaced grounding rods), or a solid wire as a return like a flag,
pennant, rectangle, or K9AY. The K9AY, because of feed and resistor
location, demands a ground rod to isolate the resistor and feed paths.
They are a different principle than the Beverage or wave antenna. The
Beverage requires some loss in earth, and stops working over very good
earth.
These small verticals in the form of loops or half-loops work better with
improved earth. They would work over poor earth, and better yet over perfect
earth.
73 Tom
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Topband Reflector
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