Roy Lewallen wrote:
Let me encourage you to build a vertical antenna and arrage a switch
so
you can switch back and forth between it and your dipole. Be sure to
use
a current balun or two in your dipole feedline so it doesn't become
part
of the test.

Here's what I think you'll find, as I have when comparing a vertical
to
a horizontal antenna. At times, one antenna will be spectacularly
better
than the other -- by 20 dB or more. After a while, maybe a minute or
so,
the signal on the good antenna will fade, and when you switch you'll
find that the other antenna is now a lot better than the formerly
good
one, by about the same amount. This cycle can go on for quite a
while.
This is likely due to polarization rotation (although multipath can
cause a similar effect, if the antennas are spaced far enough apart);

whichever antenna has the right polarization for the moment will be
much
better than the other.

Thats pretty close...They flip flop back and forth...

I don't believe you'll find any spectacular overall improvement by
using
the vertical.

Depends on the length of the path, and the frequency. On 40m at night,
the
improvement using the vertical is spectacular *if* the path is long
enough.
But that will vary. At 500 miles, usually the dipole will win.
At 1000 miles, usually they will be about even. At 1500 miles the usual
amount
on the S meter is about 2 s units in favor of the vertical. At 4000+
miles,
can be 4 s units.
But of course, this will vary to the quality of the vertical.
In my case, was a full size ground plane, 4 radials, up 36 feet at the
base.
The dipole was at 36 feet. Same height as the base of the GP.
My 40 meter mobile antenna is almost always better than my 36 ft high
dipole
to either of the coasts. I've tested that many times to Fla.
On say a 1500 mile path, usually the vertical will hold the best
overall,
maybe 90 percent of the time, but you will see the shift where they
flip flop
for a short time, and then flip back...
Sometimes the flop will leave them about equal. When back to "normal",
the vertical will be noticably better..2 s units in that 1500 mile
case...The vertical will be better a lot larger percentage of the time,
than
the dipole. I've seen many cases where the dipole never is as loud as
the
vertical, no matter what the shift...But thats usually on the longer
paths.
The longer the path, the larger the vertical advantage. To say VK land,
I've
never seen the vertical less than 3-4 s units better than the dipole at
36 ft.
And I was on about 3 times a week to check at that time. That dipole
would have
to be a whole lot higher than 36 ft to even come close to the ground
plane I ran.

When doing these tests, don't make the mistake of assuming the units
on
your S-meter are some particular number of dB, unless you have the
abililty to actually measure them. Any assumption you make could be
WAY off.

True...I make no claim to actual db increase....But I do use switches,
and get
a good A/B comparison...BTW...I think the vertical advantage on long
paths
decreases as you go higher in frequency...Maybe cuz the dipoles are
higher in
wavelength??? Not sure...Seems to be more a lower band, nighttime
thing...The
types of propagation at night vs day may be a factor...MK