I have always dreamed about a crank-up tower and an elevation rotor on a ten
meter installation. At one time long ago K1AS had a converted "Moonraker" beam
that was mounted on a slightly bent mast. He always did very well. I suspect
he caught angles that I just couldn't. Anyway, it always had me thinking of an
installation like I mentioned above. Ten meters is a band whose wavelengths
seem to make this feasible.
73 Dick - KB1H
Michael Watts wrote:
> So has anyone tried using an elevation rotor on a high yagi? Why couldn't
> you have the best of all worlds with a high yagi and point it up for high
> arrival angles?
>
> Michael WY6K
>
> --- "Guy Olinger, K2AV" <k2av@contesting.com> wrote:
> >
> > I suspect that this is not so much a matter of where the main
> > radiation pattern is, as where the nulls are in respect to the
> > incoming angles.
> >
> > Very high antennas have better gain at the lower angles in marginal
> > conditions, and those extra db's at the horizon are worth a lot. But
> > the high antennas have deep nulls at common arrival angles. It would
> > be easy and common to have the arrival angle on a minus 25 db null in
> > the high antenna's pattern.
> >
> > This would be the exact phenomenon accounting for being "stomped" by a
> > tribander. A 25 db null advantage to the tribander would be really
> > hard to beat.
> >
> > Aside from getting some gain at very low angles, that's the main
> > performing reason for stacks -- avoid pattern nulls on angle of
> > arrival.
> >
> > 73
> >
> > ----- Original Message -----
> > From: "David L. Thompson" <thompson@mindspring.com>
> > To: <towertalk@contesting.com>
> > Sent: Friday, February 01, 2002 5:21 PM
> > Subject: [TowerTalk] Super high antennas on 10 to 20
> >
> >
> >
> > N4KG and W4ZV are right. The real high antennas can be at a
> > disadvantage
> > after the bands open. I had a 7 el 10 meter beam at 70 feet in 1970
> > for the
> > CQ WPX SSB and I had a great signal into Northern and Eastern Europe
> > and the
> > Far East but needed to lower the antenna
> > to 40 to 50 feet when I got stepped on by a local with a 3el
> > tri-bander at
> > 50 feet in G or HP (then KZ5 Canal Zone).
> >
> > N4RJ tried all sorts of combinations and his final 10 meter set up was
> > 35/65/90 and about the same proportion on 15 and 20. The 35 foot
> > antenna
> > was often left on South America.
> >
> > Spend time on the lower antennas and only add antennas at 180 to 200
> > feet
> > when its the last option.
> >
> > 73 Dave K4JRB
> >
> >
> >
> > ______________________________________________________________________
> > __
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> >
> >
> >
> >
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Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
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