Sinisa,
You're the theory expert.
Each time I try to discuss theory, I mess it up, so I'll just
stay with reporting on my own practical experience and also quote
4 other sources where this antenna has been published (confirming
what I stated).
I stand by my statement that at all the clubs I've belonged to,
the loop has outperformed the dipole for the type of operations
needed for Field Day contests. That of course means to work as
many portable stations as possible, the majority of whom are in
the same country (DL in my case). I'm not talking about one
dipole that didn't perform - I'm talking about many dipoles that
didn't perform. Actually they did perform but the loop simply
performed better. The 80/40 meter difference was small and
sometimes the dipole was equal, but it was almost never stronger.
Usually the loop was stronger. On the higher bands, the loop
stomped the dipole.
Sometimes the dipoles were fed with coax with multiple dipoles
fed in parallel. Sometimes we used openwire for feeding the
dipole and a couple of times some fool actually insisted on
putting up an FD4 (dummy load).
Each time I moved to a new city, I chose the club that had the
best track record in contesting.
These weren't guy who didn't know how to build dipoles.
I could buy into your theory if this had only happened once or
twice. But it happened many, many times.
I began using the loops in 1977 right after reading an article in
the CQDL magazine (September 1997) written by DL3IS.
A second article appeared in CQDL in January of 1978 written by
Karl Hille, DL1VU, one of the top authorities on antennas in the
German ham scene, and finally a third article appeared in June of
1978, written by DL2FA.
Each of these claimed great experience with these loops for NDIS
on the low bands and good DX on the high bands.
Finally, in the early 90', Paul Carr, N4PC, did a series of
articles on these loops, including modeling on all the bands. He
expanded it with phased feeding to opposite corners to even give
low angle radiation with the 80m version (albeit with loss of the
multi-band feature). I believe the articles appeared in CQ
magazine, but I'm not sure. I still have them buried somewhere
in my shack but I couldn't find them tonight. I'll have to
search for them some other time.
All of these articles and my experience with it (which spans 25
years) point towards this antenna out-performing a dipole - but I
couldn't tell you why!
I only hope some day to have enough land to be able to put one up
permanently.
73
Rick
There is only one explanation for a loop (or anything else)
outperforming a dipole (or anything else) in ALL directions:
your dipole is wasting at least 75 % of RF energy.
Instead of claiming that "loop is always better",
it would be wiser to eliminate the loss.
And it is certainly not caused by the length of the wire,
or the shape of it.
73,
Sinisa YT1NT, VA3TTN
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