wrote:
Note the Isotron..

I suspect that the Isotron performs best when the
feedline is radiating like crazy. So the question
is: Has anyone ever tried to maximize feedline
radiation? Seems that is what the Carolina Windom
has done by accident. Can it be done on purpose?
--
73, Cecil http://www.w5dxp.com

In article ,
Cecil Moore wrote:

I suspect that the Isotron performs best when the
feedline is radiating like crazy.

That's consistent with the installation instructions that state that
it must be mounted on a metal mast.

So the question
is: Has anyone ever tried to maximize feedline
radiation? Seems that is what the Carolina Windom
has done by accident. Can it be done on purpose?

Use a simple wire or rod radiator tied to the center conductor of the
coax, no radiator tied to the shield, and a length of feedline which
is an even multiple of a halfwave (at the exterior shield's
velocity-of-propagation) back to ground or the transmitter, serving as
a counterpoise?

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Dave Platt wrote:
Use a simple wire or rod radiator tied to the center conductor of the
coax, no radiator tied to the shield, and a length of feedline which
is an even multiple of a halfwave (at the exterior shield's
velocity-of-propagation) back to ground or the transmitter, serving as
a counterpoise?

Seems to me, the "ground" would cause reflections, turn
that "even multiple of a halfwave" into a standing-wave
antenna, and maybe be more efficient than an Isotron?
--
73, Cecil http://www.w5dxp.com

In article ,
Cecil Moore wrote:

Use a simple wire or rod radiator tied to the center conductor of the
coax, no radiator tied to the shield, and a length of feedline which
is an even multiple of a halfwave (at the exterior shield's
velocity-of-propagation) back to ground or the transmitter, serving as
a counterpoise?

Seems to me, the "ground" would cause reflections, turn
that "even multiple of a halfwave" into a standing-wave
antenna, and maybe be more efficient than an Isotron?

Better be careful about that dreaded word "efficient", especially in
the context of small antennas - Art might take umbrage.

On the basis of the usual "power radiated, divided by power input",
the type I suggested *might* be more efficient than an Isotron... but
only because its losses might be lower. Most of the Isotron designs
I've seen pictured, have a tuned circuit of some sort at the feedpoint
(e.g. a big air-wound coil and a metal-plate capacitor), and there
will no doubt be some losses in this tuned circuit.

I don't know which antenna would have more directional gain at its
primary lobe, or which one would have a stronger signal in whatever
specific angle its operator found most useful at any particular moment.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!