Whoa, not so fast, as this is how the poor
"ham lore" gets started and passed around.
Source:
http://www.antennasbyn6lf.com/2011/02/comments-on-elevated-radials.html
"... During the experimental measurements on the
elevated 4-radial system I noticed that the
results were very sensitive to even small
changes or asymmetry in the radials. To get
results equal to 60 radials on the ground,
I had to carefully verify that the currents
in all four radials had the same amplitude
and phase and that the radial current phase
and amplitude sum agreed with the current in
the base of the vertical. In short, I had to
be a fanatic with the radial layout details! ..."
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The emphasis above added by me.
I suggest a careful reading of his entire
letter to QST for even more details.
How many 'hams' are educated to understand,
have the needed equipment, and are able to
make the level of measurements he mentions?
Elevated radials MAY offer a "better" option,
but to make a broad statement as below is not
accurate nor easily repeatable in practice.
N6LF does an excellent job in presenting his
results, let us do the same as to how we both
understand, and share the data with others.
73 de Billy, AA4NU
-----Original Message-----
>From: Stuart Rohre <rohre@arlut.utexas.edu>
>
>Oh Yes, Rudy is quite specific about elevated radials also.
>They are the most efficient.
>
>Just consider that dirt is not a very good conductor of RF, why would
>you shield your radials by burying them in or near a non conductor?
>Atop the ground would be the least of the lossy methods, while elevated
>radials would have the best performance as his data shows. Rudy shows
>they don't have to be elevated high to get the performance up.
>
>Radials do tune your antenna depending on their type and length, also
>covered in his experiments.
>
>Stuart Rohre
>K5KVH
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|