[SMCARA] Couterpoise Question

[Richard (KG3BOZ)]

An excellent resource for this subject is the ARRL Vertical antenna compendium.  I Highly recommend it.  Much of what it says echos Tom Clarke's comments and also matches my personal experience. 

Unless you have a resonant vertical, don't obsess about radial length.  Do as much as you can in the space available and then have fun working DX!   

Boz  


73 DE KG3BOZ

<div>-------- Original message --------</div><div>From: Bill Jones <merc669 at gmail.com> </div><div>Date:09/25/2014  09:40  (GMT-05:00) </div><div>To: "Clarke, Tom AIR4.0P NATOPS" <frederic.clarke at navy.mil> </div><div>Cc: smcara at mailman.qth.net </div><div>Subject: Re: [SMCARA] Couterpoise Question </div><div>
</div>The End-Fed antenna is the Ultimax DxExtream 77 foot antenna. This I plan
on one end in a tree about 40 feet up and slope it to 10. The balun itself
will also have a 1:1 isolation balun for RF feedback prevention near the
feedpoint and then going into the house. I have also read that length does
not matter for counterpoise and others that say run a single length for the
lowest band and have a few of these laid. All different opinions...

Bill
KC3DEZ

On Thu, Sep 25, 2014 at 9:07 AM, Clarke, Tom AIR4.0P NATOPS <
frederic.clarke at navy.mil> wrote:

> Bill,
>
> I think the answer is "it depends"!  Conventional wisdom has it that the
> length of the radials are not as critical when on the ground or buried.
> Ground conductivity gets into the act here also. Things would be quite
> different in Arizona!
>
>  In your case the 8.6 foot radial is a "tuned" radial and should be in the
> same plane as the antenna, although not critical if it hangs vertically
> (although it may affect the directionality somewhat.  In the case of the 80
> meter radial, again it should be elevated to function as a tuned radial,
> but if your situation calls for it to be on the ground, the elevation  of
> the feedpoint should not be added to the radial length, as it is all part
> of the radial length.  Since part of the counterpoise is on the ground, it
> will become detuned by the earth anyway.  There are several treatises in
> the ARRL archives concerning grounds, radials, and counterpoises.
>
> FYI, I have a ground  mounted vertical antenna and I simply have 32,
> twenty-five foot radials on the ground or slightly buried.  This works very
> well.  When I had this antenna mounted on a tile roof in EA7 land, I used 4
> elevated,  stub-tuned radials which worked very well. Adding additional
> radials on the roof did not make any noticeable difference.
>
> What kind of end fed antenna are you using?
>
> Tom/W4OKW
>
> -----Original Message-----
> From: SMCARA [mailto:smcara-bounces at mailman.qth.net] On Behalf Of Bill
> Jones
> Sent: Thursday, September 25, 2014 6:08 AM
> To: smcara at mailman.qth.net
> Subject: [SMCARA] Couterpoise Question
>
> If I need a 65 to 70 foot counterpoise for 80 Meters and a 8.6 foot one for
> 10  Meters and my balun from my end-fed antenna is 10 foot up do I need to
> add 10 feet to the math to get the counterpoise to ground level for it to
> be effective. In the example of 10 meters the wire is just hanging in air.
> These would be run opposite to the feedline. Thanks!
>
> Bill
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