Given that I can only have one antenna and it has to be a single
vertical, not exceeding 45 feet, I'm seeking advice on the best way to
achieve this.

The feed point must be at at ground level and will be 100 Metres away
fed with low loss coaxial cable.

I can lay down a good radial system and ground rod at the feed point.

I'd like to use the antenna on all HF bands, or as many as possible
from 1.8 MHz up.

My choices seem to be,

1. A commercial HF Multiband antenna eg, HF9V
or
2. A vertical wire supported by a 40'-45' fiberglass pole with an auto
ATU at the base, eg SG230.

Q . Which way to go? Naturally I'd like to achieve some low angle
radiation on some bands.

I'd appreciate any advice on which would be the most efficient system
given my constraints.

Anything else I haven't thought of ?

73, F5VJC

Deni!

How about a vertical Zepp. It does not need any counterpoise.
I did some experiments with this type of antenna. You will
find it as a 'no counterpoise antenna' via Google. It consists
of a parallel wire and on one of the two wires an extended
wire is connected.

X====================-----------------------------------------

The drawing is horizontal, but use it as a vertical antenna! At the
point
X a Balun converts from symetrical to coax - or direct into an ATU.
The Balun is a red core with a 5 turns RG-174 wound twice.
Look here http://home.datacomm.ch/hb9abx/mws.htm

I use a version on a 12m fiber glass and it gave very good results.

Drop me a line if you need more info, email: oe1mww(at)qsl.net

73
Wolfgang
OE1MWW

"Deni foxfiveVJC" skrev i meddelandet
...
Given that I can only have one antenna and it has to be a single vertical,
not exceeding 45 feet, I'm seeking advice on the best way to achieve
this.

The feed point must be at at ground level and will be 100 Metres away
fed with low loss coaxial cable.

I can lay down a good radial system and ground rod at the feed point.

I'd like to use the antenna on all HF bands, or as many as possible from
1.8 MHz up.

My choices seem to be,

1. A commercial HF Multiband antenna eg, HF9V
or
2. A vertical wire supported by a 40'-45' fiberglass pole with an auto ATU
at the base, eg SG230.

Q . Which way to go? Naturally I'd like to achieve some low angle
radiation on some bands.

I'd appreciate any advice on which would be the most efficient system
given my constraints.

Anything else I haven't thought of ?

73, F5VJC


Hi, I have used a simular setup as nr 2. I use a Chinese CG-2000 automatic
tuner and it works OK on all HF bands. Gives you alot of options on how to
attach your wire. I have used glassfiber rods and also tried a more LW like
slanting of the wire. Can really be a flexible antenna. It's not as complex
as commercial multiband antennas.

It's critical to have a good RF ground but I live close to a lake so no
problem with the radials.....

Go for nr 2....

/ SM0FKI Ulf

Deni foxfiveVJC wrote:
2. A vertical wire supported by a 40'-45' fiberglass pole with an auto
ATU at the base, eg SG230.

If the vertical is much over 5/8WL long, its take-
off-angle is too high for proper operation. 5/8WL
~600/f = 21 feet on 10m. Your 40-45 foot height
would only be good up to about 14.3 MHz unless you
figure out a way to shorten the wire above that
frequency.

Here's another idea using the same space and this
is my present vertical antenna. Make the vertical
21 feet long and locate its top at 42 feet. The
feedpoint is then 21 feet in the air. Install
elevated radials acting as guy wires at that 21 foot
level along with the SG-230. That will give you pretty
good 40m-10m operation. For reasonable 80m operation,
install a loading coil at the feedpoint, in for 80m
and shorted for all the other HF bands.

According to EZNEC, on 10m, that antenna has:

*** 4.2 dBi omni gain with a TOA of 11 degrees ***
--
73, Cecil http://www.w5dxp.com

"Cecil Moore"
If the vertical is much over 5/8WL long, its take-
off-angle is too high for proper operation. 5/8WL
~600/f = 21 feet on 10m. Your 40-45 foot height
would only be good up to about 14.3 MHz unless you
figure out a way to shorten the wire above that
frequency.
____________

Just to note that the peak field _generated_ by a ground-mounted
vertical up to 5/8 wavelength high always occurs in the horizontal
plane. Ground losses for the displacement currents in the earth
gathered by a buried radial network within about 1/2 wavelength
of the antenna will reduce this field from its theoretical maximum
value, but peak relative gain _as radiated_ always will remain
directed in the horizontal plane, regardless of the amount of
those ground losses.

Calculating the "pattern" of a vertical radiator at an infinite
distance from a site on the earth leads one to think that the
radiator produces zero field in the horizontal plane, and that
its maximum field _as it is radiated_ occurs at some higher angle.

But this effect is only due to groundwave propagation losses
related to earth conductivity, the r-f frequency, and earth curvature.
It doesn't mean that the vertical radiator originally produced
zero h-plane field -- just that the higher angle fields were the only
ones to survive the trip to an infinite distance.

If the above was not true, MW commercial broadcast stations
would have essentially no daytime groundwave coverage.
Their nighttime, distant skywave coverage also would be affected,
because much of that is produced by elevation plane radiation
between zero and +10 degrees.

RF

Visit http://rfry.org for FM transmission system papers.

Wow, I made a big post and then lost it. Take two.

I've put up a 12m Spiderbeam pole + wire + base matching networks fed
against 27 ground radials ranging from 20 to 40 feet long. I'm using
it only on 80m, 60m, 40m, and 30m, and I've been quite happy with it.
As Cecil mentioned, it should work quite on 20m as well, but on 17m
and up it will have a less than desireable radiation pattern.

I'd still recommend getting the pole and autotuner. I think the
overall efficiency will be more related to what you can get in as
ground radials than which antenna you use. I think that the cost is
probably about the same in both cases. What you get with the 40 foot
pole and autotuner approach is a 40 foot pole and an autotuner! Better
parts to try out different antennas.

As far as the bands above 17m, two suggestions come to mind.

1) For routine, easy copy communication on 17m and up, just use the
antenna as is. It's bad for low angle radiation, but you're not going
to notice the differerence when you're hearing s9 signals that could be
s9+10dB instead. If good DX that you're having trouble hearing comes
on 17m or above, go out, drop the pole a few sections, and reattach the
wire to the tuner. Voila, your too-long vertical isn't anymore.
Cecil's suggestion to use a 21 foot vertical instead is just fine, but
you lose 80m in that case, and at this point in the sunspot cycle, I'd
personally take inconvenient operation on 17 over giving up 80m.

2) An old approach using new parts, if you can run a couple of wires
out at angles from the top of the pole. Put up an inverted-vee doublet
at the top of the 40 foot pole. Make some open-wire line to feed it.
On the lower bands, feed both feedline conductors against a good radial
system. On the higher bands, feed the doublet as a doublet. I haven't
tried this due to the lack of an autotuner, but I think it could work
quite well. It doesn't exactly fit your criterion of one 40 to 45 foot
vertical, but the visual impact is the same... maybe you've got some
trees or could tie things off to the house ... it's a top loaded
vertical on the lower bands, and a nice, high inverted vee on the
higher bands.

In the middle region, probably 30m and 40m, you could pick whether you
were using the doublet or the vertical depending on who you were trying
to contact.

73,
Dan
www.n3ox.net

"Cecil Moore"
If the vertical is much over 5/8WL long, its take-
off-angle is too high for proper operation. 5/8WL
~600/f = 21 feet on 10m. Your 40-45 foot height
would only be good up to about 14.3 MHz unless you
figure out a way to shorten the wire above that
frequency.

Cecil's absolutely right about this... but, a suggestion. Right now,
above 14MHz, the bands aren't so hot. 17m is open a lot, 15m is open
sometimes, 12&10 almost never.

I'm using your setup #2 on 80m, 40m, and 30m and have been quite happy
with it. The radial field is 27 radials ranging between about 20 feet
and 40 feet (out to the edges of my yard) I'm using one of the 12m
Spiderbeam poles. I built my own L-matching networks for the base,
just because I didn't have an autotuner. I've noted good DX
performance. I don't have any quantitative numbers, but I'd make my
recommendation on another basis.

I expect a good multiband vertical costs about the same as a 40 foot
telescoping fiberglass pole + decent autotuner. Radial costs are the
same...

However, the antenna *versatility* of the pole + autotuner is much
better. You get better parts for your money. You will certainly be
able to load up a 40 foot vertical on 17m and up for noncritical
communication.... when signals are s9, you won't notice that they're
not s9+ 10dB. If some really good DX comes on 17 and conditions are
marginal, go outside and drop the pole two or three sections and
reattach the wire to the tuner! Now you've got a 5/8ths vertical on
17m!

The pole will come in handy for portable and field use; the autotuner
can be used to match whatever you want to try out in the back yard, and
having a nonconductive fiberglass support is great for experimentation.

Something I thought about trying, and would if I actually had an
automatic tuner, is rigging up a short inverted vee doublet at the top
of my 40 foot pole. It would be short enough to be only bidirectional
on 20m and up. Also install a good radial field for the low bands.
Homemade open wire line runs from the doublet at the top down to the
ground. On 80, 40, and (maybe) 30m, feed both conductors of the
feedline against ground. On 20m and up, feed the doublet as a doublet
instead. You just need a couple of relays to perform the switching
tasks remotely. This is an old approach to a multiband wire antenna
with good performance on both the low and high bands. A nice pole and
automatic tuner just makes it all the easier.

In fact, if you want to save even more money, do the doublet/vertical
thing but build one of Cecil's all-open-wire matching networks for the
higher bands. Some relays and some ladder line, a pole that costs EUR
80, and a bunch of wire, and you've got a good antenna system.

http://www.qsl.net/w5dxp/notuner.htm

One further thing to recommend the 40 foot telescoping fiberglass pole
is that you can make it easily disappear when you want to. Mine stays
inside when I'm not operating on the lower bands. Of course, I'm just
using it as a vertical; it takes 1 minute to take it outside, clip on
the guys, and raise the vertical wire. It would be a little more
involved to put up and take down a doublet all the time.


73,
Dan

Um, the old post came back... sorry folks... pick the one you like
better :-)

Dan