Nat, I would agree with Dick completely...I have had a full size 3L20 at
150ft and many times received no greater signal report than a ham down the
street with a 3L20 at 70ft. The band opening/closing situation seems to
ring true as well.
Unless one has an antenna as Dale, W6VSS had a few years back--a monster 80
meter beam, the boom of which was a Rohn 25 tower, the band opening/closing
may just not be worth the expense, effort, and required maintenance. Now I
have two beams 4L20s at 80 ft and a 3L20 at 45 ft and hear more than some
others across town with higher beam with more elements.
Terrain, ground efficiency, and surrounding terrain are big factors for us
all. Fortunately where I am, the ground is relatively flat for several
miles in all directions...and that is great!
Unless your surrounding terrain requires you to have a "periscope" to see
out, money spent on feedlines, and grounding will pay bigger dividends!
My observations are not figured scientifically, just observations from 38
years of ham radio. I have tried 5 elements on a 46 ft boom at 55ft, 3
elements on a 26 ft boom at 150ft, and now a 4 element on a 34ft boom at
80ft and a smaller 3L20 at 45 feet--this latter pair seems to do the best
job ever.
Those gains past 3L20 at 70 ft come very hard, with much expense, much
labor, and much worry when a big wind blows, not to mention the wear on
the knees and feet climbing up a really tall one.
That said, if I could buy a Big Bertha for $5k and install it for $5k, I
would probably do it, just for the thrill of seeing all that aluminum in
the air...but at the same time, that Big Bertha would be but a couple of db
better than where I am now and then ouch(!) on the knees.....so I have to
ask myself...."Just how much is enough?"
Best 73s,
Grant
W4OJC
----- Original Message -----
From: "Dick Pechie - KB1H" <rpechie@snet.net>
To: "Nat Heatwole" <nat@ajheatwole.com>
Cc: <towertalk@contesting.com>
Sent: Thursday, January 31, 2002 10:39 PM
Subject: Re: [TowerTalk] 10m-20m Antennas Above 150ft
>
> Not only do you have to decide is anything higher worth the QSO increase,
> but what is the higher antenna getting you as far as usable take-off
angle
> vs. terrain gain. I believe the very high antennas of KC1XX and W3LPL can
> open a band early but after the initial opening these two guys are in the
> pack with the rest of us. Operating skill can overtake allot of
mediocrity
> very easily.
>
> I do think that a terrain gain analysis can prevent you from making a
> decision on what I would call midsize tower heights such as 90-120 feet.
I
> found that 120 feet did not take advantage of the terrain gain to Europe
as
> well as 90 feet did on 20 meters. Thus, we only put up 90 feet on the 20
> meter tower with the bottom 204BA at 35 feet.
>
> I guess at a height of many wavelengths such as 300 feet all you are
looking
> at is a band opening advantage.
>
> Not a scientific observation but a 30+ year on the job training.
>
> 73 Dick - KB1H
>
>
> Nat Heatwole wrote:
>
> > I've noticed that both KC1XX and W3LPL have yagis for 10m-20m going all
> > the way to 200ft high. Are yagis in the 150-200ft range for those bands
> > really all that useful, or are they more of a "few QSOs per contest"
> > level of usage? I would assume that once you get above say 150ft there
> > wouldn't be a whole lot of cause to put yagis even higher, correct? Is
> > there really enough long haul DX at those heights or is it really just
> > for a handful of QSOs?
> >
> > 73, Nat, WZ3AR
> > <nat@ajheatwole.com>
> >
> >
________________________________________________________________________
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> > Order online at http://store.eham.net.
> > -----------------------------------------------------------------------
> >
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>
> ________________________________________________________________________
> Where do you get ICE bandpass filters & beverage matching boxes? The
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> Order online at http://store.eham.net.
> -----------------------------------------------------------------------
>
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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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