[Elecraft] 80 Meter Verticals

[Irma Linas]

Ted,

I would recommend very much the site of DJ0IP for tonns of brilliant ideas
on really working antennas. And also a great article of N6LF in QST March,
2010 on radials. You don't need to have 64 or 164 or a chicken mash all
over the field to get the very eficient antenna working DX. 16 is enough.
Based on these excellent sources, I have used myself with great success the
vertical on 80/40 on the 18m Spider mast with the 16 rqdials 12 m long
each. The other time , in the CQWW CW contest, I had no chance to erect the
18m Spider pole due to cold wx condx, so I put up a modernized 43ft
vertical S9 ( a fiberglass pole , actually with the 43 ft of wire inside).
Modernization has come just to adding some 6 more meters of wire to the end
of 43 footter ( making 1/4 waveln. on 80) plus a coax trap and some 20m
more of wire after it ( getting 1/4 waveln. on 160). So I had a Inverted L
with the 14m vertical part and some 26m with a trap horizontal part (
sloping down really to a 4m pole ). The same 16 12m radials stayed due to
lack of time to change them into 25 m each which would be better for 160.
Nevertheless this compromise decision brought me a good 220 qsos on 160m
and around 200 on 80, with barefoot K3 trx incl the Japanese and US
stations on 160m which , for me, was a surprisingly good score. No separate
RX antenna. The resonance was very easy to tune to with the help of the
antenna analyser Youkit FG-01.

It would have been best if I could do this trap combo on a Spider mast with
18m vertical and with 16 radials of 25m long. I will try this this coming
spring, weather permitting.

Wish you good luck and lots of fun with practical experimentation in the
field!

73! Linas LY2H





On 2017 vas. 28, an at 01:45 Don Wilhelm <donwilh at embarqmail.com> wrote:

> Ted,
>
> The inverted L will have some horizontally polarized radiation.  The
> other top loaded verticals should have only vertically polarized
> radiation - assuming that the top loading is symmetrical, whether that
> be a capacity hat or a T wire.
>
> In general, the vertically polarized radiation will be at a lower angle
> than horizontally polarized, but that all depends on the ground
> conductivity and your radial system.  A radial system of 64 radials is
> good if your ground conductivity is decent, but if you are in an area
> where ground conductivity is poor, you may have better luck with
> horizontal antennas or an inverted Vee - the higher the better.
>
> So the answer is "it all depends".  If you do not have a wonderful
> ground screen, a vertical may perform worse than a horizontal antenna
> because a lot of your RF goes into "heating the worms".
>
> 73,
> Don W3FPR
>
> On 2/27/2017 6:13 PM, Dauer, Edward wrote:
> > A question that’s admittedly a bit OT – though if I need a pretext, the
> rig to be used is a K3 . . .
> >
> > I have been reading through the usual texts about vertical antennas for
> 80 meters, to replace the half wave dipole I now have and the Vee I had but
> didn’t like.  But I have not yet found the answer to one question I am
> thinking about:  The advantages or disadvantages of an inverted L compared
> to other variations of the top-loaded vertical.
> >
> > Assume a 40-foot ground-mounted vertical section made with wire running
> up a fiberglass mast.  There could be a remote tuner or balun at the base
> if it’s needed.  The top of the vertical section would be guyed with four
> lines more or less parallel to the earth extending from the top tip of the
> vertical section to four suitably located trees.  That physical
> configuration offers three kinds of options.
> >
> > One is an inverted L.  One of the four guy lines would be a wire making
> the L and long enough to have the overall antenna resonate, with
> nonconductive line from there to the tree.  The other three guy lines would
> be nonconductive for their entire length.
> >
> > Another would be the classic top-loaded “T” vertical.  Two opposing guy
> lines would be equal-length wire out far enough to achieve resonance, with
> the other two nonconductive for their entire length.
> >
> > A third would be something closer to a capacity hat.  All four of the
> guy lines would start at the tip as wires, of equal length and just long
> enough to effect resonance, with nonconductive rope from there to each of
> the four trees.  This variation might also have a square loop connecting
> the distal ends of the four top wires.
> >
> > If the goal is to have the highest efficiency and the lowest net
> radiation angle, and if the height of the vertical section is fixed and the
> radial system is the same for each choice, does it matter which of those
> three or four options is chosen?  And if it does, how come?
> >
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