On 29 Dec, 17:55, John Smith wrote:
Dave Heil wrote:
...
Heck, Brian, I was just going to suggest that you make some
substantional portion of your antennas out of long steel springs. *You
could tie a rope to an end and change bands by simply letting out on the
rope and allowing the springs to compress, heh heh.
Dave K8MN
Actually, a very good recommendation--for some limited applications ...
I have seen just such done, only with phosphor-bronze springs, and of
limited frequency bandwidth ...
JS
John
As you know from personal experience one can make antenna with
windings
finishing at the top of the radiator, but it must be seen as being
resonant
by virtue of the added resistance. This is exactly why Prof Hately was
unsuccesful with his contraversal small broadcast band antenna
first tested in Egypt, then Australia and then the Isle of Man.
This is also also why that antenna made by that guy in Florida(Hart?)
is not as efficient as he and Hately led themselves to believe.
Remember that our latest antenna inventor from RI also used a single
winding type of antenna in a way similar to a slinky to which you
were refering to, but then you have to ask yourself why these antennas
were not efficient, and why RI and others had to increase the diameter
of the
radiator wire because their designs melted? All of these antennas
problems
can be solved just by adding to the antenna length in a contra wound
fashion back to the antenna base thus negating the need for ground
planes and thicker wire.
This is exactly why the loop antenna that I was talking about
in another thread is to be made out of #22 wire since, unlike
the RI antenna the wire will not melt because of excess heat
Instead this lost energy will now contribute to radiation .
If you refer to the thread of "current travel down the center
of the radiator" in the absence of a radiating surface you
will better understand the relationships to Gauss and static
law. That thread has now come to a satisfactory completion
as far as I am concerned.
As for Cecil's postings,that thread will never come to a
satisfactory conclusion since the moment in time has not
been stipulated. But even if one side or another was
proven correct one must ask themselves as to what advantage
is it with respect to antennas if agreement is finally
arrived at? But then it is well known in psychology circles
that agreement can never come about when one of the
parties are angry or confused which provides for
personal attack
Very best regards
Art Unwin KB9MZ...xg