"Jeff Liebermann" wrote in message
...
On Thu, 19 Nov 2009 18:46:59 -0600, "amdx" wrote:

Sure, as soon as I try to make you King you find work for me :-)

I hate to tell you this, but that's what kings are paid to do. They
give orders. Do you require a public proclamation, executive order,
or pontifical bull (in Latin), in order to be properly inspired? Now,
pleae do some testing. After all this is your antenna, your question
and your problem.

Ya, I have quad panel on the boat, when I get some time I'll try the
comparision.

Doing it on a boat might be a problem. You're too close to the water
which will probably be inside the Fresnel Zone. The water also acts
as a great reflector. Thinks also move on a vessel, making stable
readings difficult. I do my testing across a valley, where there's
little chance of ground reflections (and there's a convenient 2.4GHz
RF source from the local mountain top WISP). The path also has a wall
of 40 meter high trees on both side to attenuate any interference.

Jeff Liebermann

All that may be true, sorry King, is true.
My antennas are 14ft above the water and the signal only goes over water for
about 30ft
before a concrete parking lot fills the rest of the distance to my targets.
Total target distance
is about 600ft. The antennas are tipped upward about 10 degrees.
Here's the test I performed, I aligned the panel and the yagi on a pole
with about the 2ft between the yagi and the center of the panel. I aimed at
the target as
accurately a I could see. (Center of condo building) During testing I did
not terminate the unused
antenna.
I used net stumbler for signal strength numbers, I received 42 signals with
the Panel,
and 44 signals with the yagi.
The one signal I usually use went from -48db (panel) to -50db (yagi),
That's +2db for the Panel.
Then I did a Netstumbler screen print of the first 35 signals using the yagi
and then the panel.
I added all 35 signal strengths and divided by the 35, to get an average
signal.
(35 is all that fit the screen without scrolling)
The Panel AVE = -58.11db, the Yagi AVE = 59.9db that is + 1.79db for the
Panel.
So if you have any faith in my method, it looks like the yagi is down about
2db from the Panel.
I'm impressed, the MFJ-1800 yagi is advertised as a 15dbi antenna, the
panel
as 19dbi antenna.
Here's the Panel seller for the 19dbi panel antenna.
http://www.fab-corp.com/product.php?...cat=255&page=1
At one time I found antenna plots for it, but can't locate them now.
Here's the yagi seller.
http://www.mfjenterprises.com/Produc...uctid=MFJ-1800
Thanks, Mike
PS.
Previously a saw 33 signals, I had never tried to optimize by adjusting the
antenna, 33 was
good enough. While mounting the yagi I moved the position of the panel,
looks like
I found a better position. :-)