> First of all a 1/2 wave vertical is a voltage fed
> antenna therefore it doesn't want/need or like a radial
> system. The current portion is 1/4 wave above the feedpoint.
While the current maxima may be 1/4 wave above ground the
high E field end of the 1/2 wave vertical (or vertical
dipole) is very close to the ground. As a result a 1/2
wave vertical sustains substantial ground losses without
an adequate radial system.
WWV and WWVH had to put radial systems under their vertical
dipoles to reduce ground losses and achieve the predicted
signal strengths. The FCC requires a full ground system
under all antennas - even 1/2 wave - in the AM broadcast
service unless the station can show through field strength
measurements that the predicted/theoretical field strength
is obtained without it. Very few AM antennas are 1/4 wave -
many, particularly above 1 MHz are in the vicinity of 1/2
wave.
73,
... Joe, W4TV
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of N7mal
> Sent: Sunday, April 05, 2009 7:56 PM
> To: John Geiger; towertalk@contesting.com
> Subject: Re: [TowerTalk] Vertical vs Beam
>
>
> I have been following this thread with great interest. I'm
> curious how many
> of the guys who have responded have ever built and/or used a 1/2 wave
> vertical,,, other than me.....
> One guy said:""1/2 wave vertical won't show any gain over a
> quarter wave
> vertical unless it has a much larger
> radial system"".... First of all a 1/2 wave vertical is a voltage fed
> antenna therefore it doesn't want/need or like a radial
> system. The current
> portion is 1/4 wave above the feedpoint. Because the 1/2 wave
> vertical is a
> 1/2 wavelength it will automatically have gain over a 1/4
> wave vertical. There were several comments about the
> """"horrible/terrible"""" noise a
> vertical hears and they are useless for receiving. Those guys
> obviously
> weren't following my DXing activities this winter 75 meter DX
> season. 95% of
> the time my 1/4 vert outheard my 1/2 wave dipole, at 1/4 wave
> high. The only
> time the dipole heard better was when there was exclusively
> high angle
> propagation. The only guys, out west, who regularly beat me
> were the guys
> with multiple element yagi antennas and much much much higher
> power than my
> 100w.
>
> To 'sort-of' answer AA5JG's original question I will go heads
> up against any
> 2 ele 40 meter yagi against a 40 meter 1/2 vertical at the
> 100w power level.
> It has been my '''on-the-air''' experience the 1/2 wave
> vertical will beat
> the 2 el yagi 90% of the time, working DX. John if you have
> extra money
> laying around there is a very good performing loaded 1/2 wave
> vertical
> antenna made by hy-gain. I used one for a couple of years,
> before it took a
> direct lightening hit. It was mounted 12 feet above the
> ground. You will
> work a lot of DX with it. You won't be the first guy through
> a DX pileup but
> you will be a long, long, way from the last guy using that antenna. 73
>
> MAL
> N7MAL
> BULLHEAD CITY, AZ
> http://www.n7mal.com
> Everyone in the world is
> entitled to be burdened
> by my opinion
>
> ----- Original Message -----
> From: John Geiger
> To: towertalk@contesting.com ; dx-is@yahoogroups.com ;
> okdxa@mailman.qth.net
> Sent: Sunday, April 05, 2009 5:39
> Subject: [TowerTalk] Vertical vs Beam
>
>
>
> I have a question for the group about experiences with
> different antennas:
>
> I was looking at a recent issue of CQ at the local bookstore
> tonight (it
> wasn't the April issue) and in a column dealing with semi
> stealth antennas,
> they mentioned that a 3/8 or 1/2 vertical will show
> comparable performance
> to a 2 element yagi. Is this true? Will such a vertical
> really do as good
> as a 2 element beam?
>
> Also, how would a roof mounted 1/4 wave vertical compare to a
> 2 element
> tribander at a low height-like 25 feet or so?
>
> 73s John AA5JG
>
> _______________________________________________
>
>
>
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