I have a full-size 40m 4-square with aluminum tubing elements and 60 ground
radials per element. Dumped power is under 2% in the CW portion of the band.
F/B is 20-30 dB.
Over the past 8 years, I've had a 40-2CD at 50', 75', 72' and 110' (the same
antenna on different towers.) I now have a Cal-Av 2D-40A at 110'.
It was very rare for the 4-square to be as loud as the 40-2CD at any of the
heights listed above. At 50', the difference was at least one S-unit. At 75'
and above, the difference could be anywhere from 1-2 S-units. However, the
40-2CD's F/B was quite poor, probably somewhere in the 10-15 dB range. This
was bad for DX-only contests, good for contests in which the USA counts.
Nonetheless, the 40-2CD was clearly the superior antenna.
The Cal-Av, with its full-size dual-driven elements is another story
altogether. It's louder than the 4-square by a wide margin. I'd say it's
typically 2-3 S-units louder. Interestingly, it *sounds* a lot louder in
comparison to the 4-square than the 40-2CD did. I think this is because the
Cal-Av is a quieter antenna and I'm hearing less noise with it (i.e., noise
on the 40-2CD would move the S-meter without improving the S/N.) The Cal-Av
F/B is 20-25 dB across the band, comparable to the 4-square.
When I had only the 4-square, my 40m contest scores were OK, but lagged the
top-ten contenders. After putting up the 40-2CD, my scores became more
competitive. I can't count the number of times I couldn't bust a pileup with
the 4-square but was able to do so easily with the 40-2CD. In the first
contest I did after putting up the Cal-Av (2008 CQ WPX), I broke my personal
best QSO total on 40m. My conclusion: yagi is almost always better than
4-square.
All that said, I currently have the 4-square and Cal-Av setup for diversity
reception using a K3, which features identical receivers and filters. The
Cal-Av audio feeds into one ear, and the 4-square audio feeds into the other
ear. If a signal is louder on one of the antennas, it will seem to be
located closer to the ear into which that antenna's audio is being fed. Most
of the time, signals are louder on the Cal-Av. But it's not unusual for
signals to be about the same on both antennas (centered), or sometimes
louder on the 4-square. Typically, this phenomenon doesn't last long, but
it's worth noting that having antennas with different peak angles can be
helpful. Also, the two antennas tend to react differently to noise like
static crashes. Overall, diversity reception with the two antennas is almost
always superior to using one or the other antenna alone.
YMMV.
73, Dick WC1M
> -----Original Message-----
> From: Bill Parry [mailto:bparry@rgv.rr.com]
> Sent: Thursday, January 01, 2009 7:57 AM
> To: RLVZ@aol.com; towertalk@contesting.com
> Subject: Re: [TowerTalk] 40-m. 4-Square vs. 40-m. Yagi - Update
>
> 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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