Hi John -
My conclusion is that "there aint no free lunch". I have designed and
installed a four direction, dual (spaced 140 feet) , phased, pennant,
receive system. It works very nicely but nothing like a good beverage. At
least two "locals" (i.e.within 100 miles) with beverages hear much better.
Since you can't make the dx transmitted signal any stronger, the obvious
answer to hearing them better is to improve the SNR. The problem with what I
call the EWE class antennas is that while they have a very nice sharp null,
at some vertical angle, off the back, that certainly does keep out a lot of
noise, the forward lobe tends to be quite broad, both vertically and
horizontally, thus letting a lot of unnecessary noise in from the desired
azimuth. Beverages get a more confined lobe by shear length, which is fine
if you have the space. Many who have both beverages and a 4 square find not
much difference in receiving since the 4 square also has fairly confined
forward lobes. Up to a point there's no real substitute for height (or
extreme length in the case of the beverage) to compress the lobe vertically
for either horizontal or vertical antennas. That's why the EWE class
antennas have very broad vertical lobes. And horizontal lobe compression is
perhaps best obtained by phasing multiple elements. That's why the 4 square
works so well - full quarterwave verticals and multiple phased elements.
My next try for 160 RX is going to be a reversible 3 element endfire with 25
ft elements, using the two outside elements for broadside. I expect it to
work better than the pennant array, but still not as well as the beverages.
But then, even with only 100 foot element spacing, it will take a bit of
real-estate and taller verticals would also help reduce the forward lobe
size.
Phased, short, vertically stacked, dipoles is another one I may look at.
Gene / W2LU
----- Original Message -----
From: "John Becker" <johnb3030@comcast.net>
To: <towertalk@contesting.com>
Sent: Tuesday, August 13, 2013 10:09 AM
Subject: [TowerTalk] Comparing Hi-Z Receive Arrays and KB7GF Shared Apex
Loop
I too am looking for something that will improve my ability to receive weak
signals on the low bands. Specifically, something that will help me work my
last 4 zones on 80 (22, 23, 24, and 26).
Any thoughts as to how these two systems would compare for that? I have
room for either, but not for a beverage. I'm not on 160, so that isn't a
consideration. Thanks!
73,
John, K9MM
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