I am really surprised to hear that your vertical does better than your XM. I
cannot actually state that I have done any comparisons of the Cushcraft to a
40 M vertical or 4 square, but I have always felt that my "short-forty" was
sorta magic. Mine is at 1 wavelength or about 135 feet and it really works
extremely well. I frequently get remarks that I am the loudest signal on
the band from EU and JA. I usually get through pileups on the first call. We
used to use the same configuration at 6D2X and generated massive pileups
into EU and JA and was in fact it was our "bread and butter" band.
As you know, those kind of reports do not take the place of real comparisons
like you have done but I would be suspicious of the results that you have
gotten. I had a problem with my XM 420 this summer. After a lightning strike
it acted like something wasn't right but the SWR was still fine. I took it
down and the Reflector coils were "fried". Maybe there is a problem with
your reflector.
Incidentally, I have noticed that some have complained that the antenna is
not broad banded enough. Mine covers from 7.0 to 7.2 with SWR under 2.0 to
1.0. This seems to be pretty reasonable for this antenna, and the antenna
still works fine above 7.2.
I would use whatever works the best, though!
Happy New Year
Bill W5VX
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of RLVZ@aol.com
Sent: Thursday, January 01, 2009 12:24 AM
To: towertalk@contesting.com
Subject: [TowerTalk] 40-m. 4-Square vs. 40-m. Yagi - Update
Guys,
Thank You for the quick replies that stated the "Shorty-Forty should be
doing
much better". That's what I originally thought too or I wouldn't have put
up
the antenna.
Some asked "what type of Shorty-Forty"? It's a new Cushcraft XM-240 that
was
cut for Mid-Band. The resonant frequency turned out to be 20khz higher than
the chart. (1.2 to 1 SWR).
Tomorrow I will take a look at the Shorty-Forty with a AIM 4170 antenna
analyzer.
Since several people indicated that the Forty-Shorty should be working much
better than it is I need to back track and clarify the ground system of the
1/4
wave vertical. I didn't tell the whole story about the 1/4 wave vertical:
it's mounted 30' out in a saltwater river that has a pretty clear saltwater
path
to Europe, Africa, and South America. (I'm about 2 miles from the Atlantic
Ocean and there are numerous small barrier Islands in between... but it's
mostly saltwater river) The reason I listed "average ground conductivity
and a
reasonable radial system" is because the vertical has no radials and just a
single corroded ground strap going down into the salt water... and I've been
told
that isn't sufficient to connect to the saltwater.
Perhaps the vertical is making better connection with the saltwater than
expected? If so, would that be the reason the simple 1/4 wave vertical with
no
radials is equal in performance to the Shorty-Forty at 90' on DX qso's... or
do
you still think I have a problem with the Shorty-Forty?
One more thing, to the West where the vertical does not have a saltwater
path, the Shorty-Forty is 10-15db better. But since the vertical has no
radials
and no saltwater to the West I'd expect at least that much difference.
73,
Dick- K9OM
In a message dated 12/31/08 11:13:18 PM Eastern Standard Time, RLVZ@aol.com
writes:
> I'm not impressed with the performance of a 2-el. Forty-Shorty at 90' on
DX
>
> qso's. While it's great for 1,000 mi. or less... my single 1/4 wave
> vertical
> is just as good on the average DX contact. (since the Shorty-Forty at 90'
> doesn't have any gain at low radiation angles... I guessed I should have
> expected
> as much)
>
> Question: Considering flat terrain, average ground conductivity, and a
> reasonable radial system: do you predict that a 40-m. 4-Square would
> outperform the
> 90' Shorty-Forty by 3-5dB on the average DX qso?
>
> 73.
> Dick- K9OM
>
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