[Elecraft] OT: Elevated vs. Buried Radials

[tomk7zz .]

Can we possibly get back to topics that are relevant to Elecraft
equipment.  Find a different forum to talk antennas!

73,Tom (K7ZZ)


On Sat, May 18, 2013 at 11:36 PM, Oliver Johns <ojohns at metacosmos.org>wrote:

> ELEVATED RADIALS:  I think Joe hits it on the head here.  A vertical with
> elevated "radials" is essentially an OCF dipole.  There is no particular
> reason for the "radials" to be a quarter wavelength.  They should be
> whatever length lets you resonate the antenna with a feed impedance you can
> live with.
>
> IMPT POINT:  If you want your antenna actually to have a vertical
> radiation pattern (low angle, omni-directional) then the elevated radials
> must be symmetric.  If there are two, they must be of exactly equal length
> and point in exactly opposite directions.  If there are four, they must be
> equal and point in directions 90 degrees from one another. This symmetry
> guarantees that the "radials" do not radiate.  The do carry currents, they
> do help resonate the antenna, but if they are symmetric radiation from them
> cancels and they therefore do not radiate appreciably.
>
> 73,
>
> Oliver
> W6ODJ
>
>
> On 18 Jan. 2013, at 06:46 AM, "Joe Subich, W4TV" <lists at subich.com> wrote:
>
> >
> > > Personally, I do wonder about the new fangled "no radials required"
> > > antennas. But, I have an old R5 and it works well.
> >
> > The "no radials" antennas are basically a vertical OCF - the short
> > decoupling radials are the short leg and the vertical is adjusted
> > through the use of traps, stubs and/or loading to resonate on the
> > desired band with the fixed length (typically 42") of the short
> > "radials".
> >
> > 73,
> >
> >   ... Joe, W4TV
> >
> >
> > On 5/18/2013 9:25 AM, Bill wrote:
> >> The cleanest installation is to put the radials in the ground - but, not
> >> portable at all. The idea is a capacitance connection with the earth. I
> >> have used welded steel cattle fence in the past - I build a mat that is
> >> about 30 or 40 feet out from the base of the antenna.
> >>
> >> For raised radials - they must be resonate to function properly. Three
> >> or four per band or related band. They have to be high enough that they
> >> present no danger to anyone roaming around your antenna field. They can
> >> be drooping or horizontal - both work well.
> >>
> >> Personally, I do wonder about the new fangled "no radials required"
> >> antennas. But, I have an old R5 and it works well. Perhaps the way to go
> >> is a new antenna that just gets bolted to a post and a feedline
> >> attached. Sure makes life easier and from folks I talk to all the time -
> >> they do work. Forget that they are a little expensive. You buy an
> >> antenna to use for years.
> >>
> >> Read the eHam reviews and see what other users are saying before you buy
> >> anything. Ask on the air.
> >>
> >> The best I ever had was a Butternut of some kind over a bunch of buried
> >> fence. Might still be the way to go. But, if I was doing it now, I'd be
> >> looking at a "no radials required" antenna. My reasoning is somewhat age
> >> related.
> >>
> >> Be looking forward to the sage advice that will come from this post. It
> >> is summer - so it is antenna time.
> >>
> >> Bill W2BLC
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