On Wed, 7 Jul 2010 14:56:59 -0400, "Ralph Mowery"
wrote:

Over the years I have seen many patterns for horizontal dipoles and the
inverted V antennas,but do not recall seeing any V shaped patterns in the
books. That is a dipole that is supported on the ends, but sag in the
middle. I know the sag is needed to some extent because of the weight of
the wire and feedline, but what happens to the pattern if it is say 1/2
wavelength or 1/4 wavelengths at the ends and the sag in the middle is
changed. Maybe drop it a few feet, then 10, 15 and 20 feet for 80 meters.

I know that for maximum distance you usually want the high current portions
up high,but maybe it will be better as a close in or omnidirectional antenna
if the center is lowered somewhat.

My initial EZNEC models of this antenna have not encouraged me to
continue.

In addition to other issues, the pattern tends to be straight up.

I will make certain that any dipoles I put up in the future will have
the center at least as high as the ends.

OTH, I will put on my DO LIST to investigate the characteristics of
turning the antenna on its side. If the pattern merits, I will
consider the matching situation.

Very interesting!
John Ferrell W8CCW

John Ferrell wrote:
On Wed, 7 Jul 2010 14:56:59 -0400, "Ralph Mowery"
wrote:

Over the years I have seen many patterns for horizontal dipoles and the
inverted V antennas,but do not recall seeing any V shaped patterns in the
books. That is a dipole that is supported on the ends, but sag in the
middle. I know the sag is needed to some extent because of the weight of
the wire and feedline, but what happens to the pattern if it is say 1/2
wavelength or 1/4 wavelengths at the ends and the sag in the middle is
changed. Maybe drop it a few feet, then 10, 15 and 20 feet for 80 meters.

I know that for maximum distance you usually want the high current portions
up high,but maybe it will be better as a close in or omnidirectional antenna
if the center is lowered somewhat.

My initial EZNEC models of this antenna have not encouraged me to
continue.

In addition to other issues, the pattern tends to be straight up.


That's likely because the effective height of the antenna is low. A
low antenna on 80m means cloud/worm warmer. (and low, in this context,
means 20m, which is still way up in the sky).

So the traditional single support inverted V has all sorts of advantages:
only one support needed
puts the important part of the antenna (the middle) up high

"Jim Lux" wrote in message
...
..


That's likely because the effective height of the antenna is low. A low
antenna on 80m means cloud/worm warmer. (and low, in this context, means
20m, which is still way up in the sky).

So the traditional single support inverted V has all sorts of advantages:
only one support needed
puts the important part of the antenna (the middle) up high

For many it is difficult to get an antenna up more than 60 feet. That is
close to 1/4 wavelength or less. My back yard has trees on each side and
it was easy to string a dipole close to 60 feet on the ends,but no way to
support the antenna in the middle. That was why the question of should I
string the dipole as tight as possiable with out breaking or adjust the drop
in the middle to some optimum distance for what I want to do. I sort of
thought the mort horizontal it is the beter the signal would be at a
distance, but there may be an optimal angle to have a 200 to 300 mile
antenna.

On Fri, 9 Jul 2010 14:08:17 -0400, "Ralph Mowery"
wrote:

For many it is difficult to get an antenna up more than 60 feet. That is
close to 1/4 wavelength or less. My back yard has trees on each side and
it was easy to string a dipole close to 60 feet on the ends,but no way to
support the antenna in the middle. That was why the question of should I
string the dipole as tight as possiable with out breaking or adjust the drop
in the middle to some optimum distance for what I want to do. I sort of
thought the mort horizontal it is the beter the signal would be at a
distance, but there may be an optimal angle to have a 200 to 300 mile
antenna.

Hi Ralph,

John's suggestion of using EZNEC in its free version would easily
answer all the questions, test all the assertions, and find all the
unstated characteristics in one fell swoop. It would also let you
find the necessary attributes to obtain your goal.

EZNEC would do all this faster than the 12 blind men trying to
describe an elephant.

However, as for your several questions above. You are not going to
discover gold at the end of the rainbow by tightening the droop. In
fact, getting it to an optimal height (as has been hammered home
several times as a principle necessity) won't budge your distant
contact's S-Meter more than a couple dB (about the width of the
needle).

73's
Richard Clark, KB7QHC

On Fri, 09 Jul 2010 09:30:55 -0700, Jim Lux
wrote:

John Ferrell wrote:
On Wed, 7 Jul 2010 14:56:59 -0400, "Ralph Mowery"
wrote:

Over the years I have seen many patterns for horizontal dipoles and the
inverted V antennas,but do not recall seeing any V shaped patterns in the
books. That is a dipole that is supported on the ends, but sag in the
middle. I know the sag is needed to some extent because of the weight of
the wire and feedline, but what happens to the pattern if it is say 1/2
wavelength or 1/4 wavelengths at the ends and the sag in the middle is
changed. Maybe drop it a few feet, then 10, 15 and 20 feet for 80 meters.

I know that for maximum distance you usually want the high current portions
up high,but maybe it will be better as a close in or omnidirectional antenna
if the center is lowered somewhat.

My initial EZNEC models of this antenna have not encouraged me to
continue.

In addition to other issues, the pattern tends to be straight up.


That's likely because the effective height of the antenna is low. A
low antenna on 80m means cloud/worm warmer. (and low, in this context,
means 20m, which is still way up in the sky).

So the traditional single support inverted V has all sorts of advantages:
only one support needed
puts the important part of the antenna (the middle) up high
The model I was working with was at 14 mhz with the feed point at
about four feet.
John Ferrell W8CCW