On Nov 7, 10:48*am, "christofire" wrote:
"Art Unwin" wrote in message

...
On Nov 6, 9:10 pm, tom wrote:



Art Unwin wrote:
On Nov 5, 10:11 pm, tom wrote:
Art Unwin wrote:
What is the best antenna for use with all circular, horizontal,
vertical and other polarizations without drastic fall of in gain, and
without changes in angular position and feed point via switches e.t..c
at the tower top?
Maybe the quadrifilar helix.

tom
K0TAR

That is made for a single circulation signal only.

Then it's a point driven against ground that you need. Or a 2 point
dipole. Either one with a lossless transmission line would work.

That's the only thing that will do all you want and do both RHC and LHC
polarizations and do it at all frequencies. I have to assume you want
all frequencies since you haven't responded on that question.

And it will have a very unusable impedance at all frequencies. But if
you can do the lossless line, you are probably covered on the lossless
tuner, too.

Good luck. You want everything, and you can't have it.

And "single circulation" is not the proper terminology (as usual),
although I am somewhat sure about what you meant.

tom
K0TAR

I wanted to know if there was such a radiator in the system that could
do such a thing and apparently there is not! I am working on one that
will do it but I wanted to be sure if I was
not reinventing the wheel.
My antenna is based on using something like a ladder line only with
the wires closer together to provide a lower impedance. If you close
both ends of such a line and wind a helix with it you can get a
radiator beam that will do all the things I suggested except the "all
frequency" part which requires further additions .
If you have two open wires in parallel and slide a cross connector up
and down the two wires the resonant frequency changes dependent on the
length where the jumper is.
Thus, if you literally make the ladder line into a true ladder by
fixing a lot of conductive cross rungs on the ladder, the applied
current will cross over at the point that the circuit is resonant.
This way the radiator will get the "all frequency" attributes.
Such a radiator becomes a much physically smaller radiator than is
being used today.
Why not try it.?... It is the proverbial free lunch!

Are you saying a wave on a transmission line will continue to propagate
beyond a short-circuit across the line? *If so, you've missed something
important.

Chris

Not sure what you are getting at Chris.
The applied current will travel the 1/2 WL of the radiator/
transmission line and then turn so it will be at resonant impedance at
the input, at the impedance value of the line. The current will not
continue to travel any further than when the closed circuit that is
resonant is reached. In other words, a transmission line can be seen
as having the same impedance or load at each end at a given frequency.
If you close one end, is it not still resonant? If you want to dig
further look at my home page unwinantennas to see where I am coming
from.
This is the same principle used when matching a radiator with
transmission line sections as shown on a nearby current thread ( at
least that is the way I see it but then I could still be a fraud by
any other name!) I have done this many times in practice BUT it may
well be the "why's) that I am misinterpreting.
On the other hand I cannot see how a AC circuit wil short across as
you have intimated.
Again I could be wrong as usual! When I model such an arrangement it
provides gain in the order of 10dbi +/- 1.5 db regardless of the type
of radiation that is directed at it. Well one type doesn't work out
well but I don't know where it is usedn in today's world