(Richard Harrison) wrote in message ...
Art, KB9MZ wrote:
"I can up my efficiency to 50 per cent by hanging a wire down from the
dipole ends which I am not comfortable about---."

Why would Art be uncomfortable about improving efficiency by hanging a
wire down?
Maybe he does not believe his model is correct. Maybe he doesn`t want
some directivity change that comes with hanging a wire down. Maybe there
is some physical problem with hanging a wire down.

The problem with a loading coil is increased loss. Capacitance is
usually low loss.

Richard
seem like a sentence got dropped,
What is it that you want to know ?
Are you suggesting using a capacitive coupling instead of
the use of an inductor.........
I think you need to rewrite the post so I can see what your needs are
Regards
Art



As Yuri, K3BU has noted, there is much to be learned from reading
ON4UN`s Chapter 9 about antenna loading even though everything regarding
vertical antennas doesn`t translate readily to horizontal antennas.

ON4UN includes horizontally polarized antennas in "Low-Band DXing". It`s
easy to read, well illustrated, and full of good references. It helps if
you want to design your own antenna because it tells why as well as how.

Best regards, Richard Harrison, KB5WZI

Art, KB9MZ wrote:
"Are you suggesting using a capacitive coupling instead of an inductor?"

The dipole is about the simplest standing wave antenna. Its system must
be resonant to allow full current in the antenna.

The best arrangement for a dipole is a centerfed balanced pair of wires
in a straight line that is self-resonant but this is only possible at
discrete frequencies.

If an antenna is too short to be resonant, it may be resonated by adding
to its inductance or its capacitance, or both, if the antenna can`t be
lengthened.

My remark was only a reiteration of common knowledge. Coils are lossy
and capacitors tend to be nearly lossless.

Cecil has shown how an all-wave system with small losses can be made
that doesn`t even require a tuner. He uses a variety of selected ladder
line lengths to maximize antenna current.

Another option is to use a balanced dipole with a balanced line
connected with the transmitter through a tuner.

Bill Orr, W6SAI has a suggestion for reducing the range of impedances
the tuner must handle. It is to make the sum of the dipole length and
the feedline length into preferred sums. These are 110, 133, 177, or 212
feet. He shows how to make the dipole, balanced line, and tuner in his
book "Wire Antennas". He calls the dipole, line, and tuner: "A Universal
H-F Antenna System", to cover 3.5 to 29.7 MHz with one antenna.

Best regards, Richard Harrison, KB5WZI