[Elecraft] Radials for vertical

[Walter Underwood]

There is a lot of work on number and length of radials. You can get a good ground with anything from 16 1/4 wave radials to 120 1/10 wave radials buried. Elevated 1/4 wave radials work well with only 2, though 4 is nice.

The experiments on this are either in the ARRL Antenna Book or the ON4UN Low Band book. I'll try and track it down.

You may have rocky, low-conductivity soil, so radials could be much more important.

wunder
K6WRU

On Jun 29, 2014, at 12:35 PM, Fred Jensen <k6dgw at foothill.net> wrote:

> On 6/29/2014 12:07 PM, Doug Person via Elecraft wrote:
>> 
>> So now I have all this aluminum wire that I would hate to throw away. So
>> I'm thinking of making a really good ground plane and putting up a
>> vertical of some kind.  I have enough scrap tubing to make about 38' or
>> so.  I was thinking of putting a remote tuner at the base of the
>> vertical as the length of coax to reach it will probably be at least 150'.
> 
> I assume you mean a ground-mounted vertical?
>> 
>> So I'd be interested in comments on how to configure the radials in
>> terms of length and number.  I know there's some guys on this reflector
>> that real know a lot about this sort of thing.
> 
> I know just about enough to get in trouble.  That said,
> 
> There is a small "Cult of the 43 ft Vertical" in ham radio ... ground-mounted, ATU remoted at the base, with a ground-plane.   If "38' or so" means getting to 43 ft, great.  If not, there really isn't a huge amount of magic in 43 except that it's a prime.  You have two choices:
> 
> 1.  Bury [like 6 inches deep] as many wires as you can, radiating out from the base of the antenna in all directions.  Length is not critical but at least 1/4 wave on your lowest frequency is good, nor do they all need to be the same length.  They don't even need to be straight. Ground planes for AM broadcast stations will often have one radial every degree around the vertical.
> 
> 2.  Elevate them a foot or two off the ground.  In this case, length *does* matter, you'll need a few [like 4?] a little over 1/4 wave long for each of the bands you'll be using it on.  This will likely also trip your cows.
> 
> Ground-mounted verticals, at frequencies where they are about 1/4 wave high will have fairly low angle radiation.  On higher frequencies where they are substantially longer electrically, they'll squirt your RF in several lobes, not all of which are useful.
> 
> 73,
> 
> Fred K6DGW
> - Northern California Contest Club
> - CU in the 2014 Cal QSO Party 4-5 Oct 2014
> - www.cqp.org
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to wunder at wunderwood.org

--
Walter Underwood
wunder at wunderwood.org