On Sat, 29 Jan 2005 10:52:05 -0500, Buck wrote:

Someone correct me if I am wrong, but isn't gain derived by narrowing
focussing all the energy into a more narrow path?

Hi Buck,

Thanks for the invitation (but we are a rabble of party crashers
anyway). What you say about narrowing to achieve gain is a useful
analogy, but there are some problems on down the line:

Besides, TOA is important to the location of an antenna in respect to
its relative position to the ground and the surrounding terrain.

True, except to invert the inference: location and terrain is
important to the TOA (put the horse before the cart, in other words).

I have heard that people surrounded by mountains prefer a 1/4 whip on
their cars for 2 meters and up when trying to hit repeaters due to its
higher angle of radiation, but in the flat areas, the preferred
antennas are the 5/8 wave etc due to its horizontal gain.

This reveals the problem with testimonial in place of measurement.
Unless you are in the Grand Canyon, you stand a chance of
communication at a very much greater distance to a mountain than you
are to another rig on the same plain. Even an HT has enough power to
communicate with a sattelite (or space shuttle). This reveals that
power is not the problem for considerable distance. However, at this
frequency (2M) line of sight on the plains is not that very far away
(less than 5 miles with your HT in your hand). On the other hand, if
on the plains you can see a mountain 50 miles away, you are as likely
as not to be able to talk to it to (presuming a repeater inhabits its
peak).

Hence the gain differential of quarterwave and 5/8ths is not
necessarily required for the Power nor the TOA - other issues are at
work. When the issues are not discussed, nor investigated, then
changing the antenna system from one to the other may resolve that
hidden issue and the difference attributed to the antenna - voila!
testimony offered.

I did an experiment when I first received my General license to see if
I could sign into the GA SSB NTS Net. I rolled out a spool of wire on
the ground approximately 1/4 wave for 3975 kc. Without a tuner I was
able to get acceptable SWR and checked into the net. I wasn't the
strongest signal but I did well enough to hold several QSOs. It
wasn't as good as my dipole when I raised one, but it worked better
than my 40 meter dipole at the time.

You have a bad habit of comparing the qualities of one antenna on one
band to the qualities of a second antenna on another band. This is
called testimonial, and it is not very useful in demonstrating
correlations. Trying to draw two different observations under the
same umbrella of discussion does not lead to any general conclusion.

Your 80M antenna on the ground would match, certainly when so
obviously in the grip of ground. You could have probably qualified
that installation to match at nearly any frequency - if we confine the
goal of matching to present no reflected power. A ground hugger so
qualifies and the ground is content to absorb (without reflecting) all
the power you pour into it.

What you fail to compare is how it worked "better" than your elevated
40M: how far were you working 80M contacts? The ground laid antenna
was used in Desert Storm for just this quality and it provided useful
contacts in missions there, but they were not interested in skip.

However, I was reading in CQ or QST last year about a DX operator who
uses verticals near the sea and wins his contests because of his
antennas. He finds the best location for his antennas near the ocean.
I believe he said he had tried beams before but there is an ocean
effect that makes the verticals better suited for his operations.

This, again, is testimonial. However, it is often attended with
compelling testing and theory that dovetail. The simple explanation
is that the vertical's radiation is constructively reinforced at low
angles by the sea, a horizontal's radiation is destructively combined
by the sea at low take off angles. The difference at very low angles
is far in excess of a 'little' db.

If you look over your shoulder to all that sand behind you, then that
same vertical becomes a miserable performer in comparison to those
beams turned to follow your eye.

Another DX operator suggests that most people will have a better
chance of communicating with him if they use a slanted dipole pointed
in the direction of their QTH. The angle of radiation and gain make
it a great DX antenna.

It's surprising how many Hams have missed this gem of wisdom. It must
mean that
1. We are a particularly dull and stupid lot;
or
2. It doesn't really offer all that much for the effort.

73's
Richard Clark, KB7QHC