W0RI wrote:
>I think you hit the nail on the head. I know quite a few locals that have
low horizontal antennas on 160 and 80 meters.
Yes they work a lot of DX, but when the rare one comes on, they have to wait
and wait.
I wouldn't trade my shunt fed tower for anything except 4 of the same
phased.
I wouldn't either Price, but having used both high-angle and
low-angle systems at the same time both here and in Colorado, I can
tell you there definitely ARE times when a vertical array will NOT
work as well as a high-angle radiator. I don't have a 4-square, but
a 3 element parasitic vertical which has about the same gain at low
angles. There are definitely times when it takes a 10 dB back seat
on long-haul DX to a simple inverted-V which is optimized to radiate
straight up. 95% of the time the low angle system is better, but I
would not want to be without the inverted-V as an alternative.
Take a look at the first elevation plot on the page below. The
blue line is the inverted-V and the black line is the vertical array.
For takeoff angles (TOA) above 40 degrees, the inverted-V wins. For
the cases I've seen when an inverted-V is 10 dB better, that implies
TOA'S of 70-90 degrees. This is not common for DX, but it does
happen more often than many might think, especially if you don't
have both antennas available to compare instantly.
http://users.vnet.net/btippett/new_page_10.htm
The other interesting thing is that when high angles are predominant,
Beverages don't work very well because they are low angle antennas.
That is usually my first clue to check the inverted-V, which is often
best for both RX and TX in such conditions.
As someone once said, you can't have too many antennas,
which applies to takeoff angles as well. If I only had to pick one
antenna for DX, it would definitely be a vertical at most latitudes.
If I were at an equatorial latitude, I might choose a high angle
antenna due to some of the things we know about loss effects due to
magnetic coupling near the electron gyrofrequency. But the best
solution is to have multiple antennas available to cover all TOA
conditions.
http://lists.contesting.com/archives/html/Topband/1999-10/msg00028.html
http://lists.contesting.com/archives/html/Topband/1999-10/msg00029.html
73, Bill W4ZV
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