N4KG comments inserted below.
On Mon, 23 Jul 2001 "Tom Rauch" <w8ji@akorn.net> writes:
>
> > The 6-12 degree region contains the first arrival angle distribution
> > peak. It takes a dipole at 160' to put much energy there. A
> vertical isn't the answer to cover these lower angles -- unless you
have
> excellent ground conductivity. EZNEC shows that verticals are also
poor
> performers at these angles there in areas of conductivities in the 2-5
range
> (my QTHis 2.5.) Of course, if your vertical antenna is on a salt
marsh,
> you win.
What TRANSMITTING and RECEIVING antennas
were assumed for these propagation models? N4KG
>
>
> Modelling prompted me to install a 318 ft tower, and that probably
> was one of the worse investments I ever made. But hey, if you don't
> try one you never know. Don't sell a vertical short without trying
> one, at least not on the lower bands where things may work out
> better than you expect!
>
> On 1.8MHz, I have a dipole at ~300feet. At best it just ties a
> series- fed 200ft tower. Most of the time the 200ft tower is better,
> and that's true at any distance!
>
160M and 80M just don't play the same, at least not
in ALA. N4KG
> My soil does not seem to be particularly good, it is clay with a
> thin layer of sandy topsoil although this is gentle rolling
pastureland
> and woods.
>
> On 80 meters at my old QTH near Atlanta, a 35 foot top loaded
> vertical with 60 80 foot radials tied or beat a 100-120 foot high
> dipole into Europe night after night.
From North Alabama, my 130 ft high dipole is usually
better to most of Europe and Africa than my elevated GP
or ground mounted wire vertical. There ARE times when
the GP or vertical are better, especially to Northern EU.
The verticals are always better to the Arctic which never
comes in well on 80M in ALA, either in the evening or
around sunrise when W0's give JW5NM 59 reports and
W8's are giving 57 reports. At best, he is 33 in ALA
but workable. Thank goodness he hears well! Similar
story with R1FJL etc.
At sunrise and sunset, the high horizontal wires are usually
better on the LP or SKEW path to SE Asia and VK0HI.
My first QSO with my 140 ft JA / SA inverted vee was
VK0HI (LP) followed by S21XX (LP), V85HG (SP?), BV, BY,
and other LP SE Asians. My 140 ft NE /SW dipole was
definitely my best antenna for the SW SKEW path to BQ9P,
XU7AAV, 8Q7. A local (inv vee) worked VU4GDG on 80M
LP when my 80M inv was damaged and I could not penetrate
the pileup with an elevated GP and sloping radials fed
at 45 ft on a 75 ft tower topped with a 3L20. Immediately
after that disappointment, I built my "N4KG special"
elevated GP (a 40 ft tower topped with TH7, reverse fed
at 15 ft with 10 horizontal radials). It has been a good performer.
I have worked XZ using both verticals and dipoles at both
sunrise and sunset on 80M. Sometimes blowing right through
and sometimes being the LAST station to get through an opening.
Bottom Line: It is good to have BOTH vertical and horizontal
antennas on 80M. A GOOD vertical with 30 or more radials
is always a useful antenna to supplement your arsenal on the
low bands. Tom N4KG
>
> I hope to have an 80 meter vertical up here someday to test against
> my 160 foot high dipole. Of course I always use real ground
> systems with lots of radials.
> 73, Tom W8JI
> W8JI@contesting.com
>
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