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 <k6...@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@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 wun...@wunderwood.org -- Walter Underwood wun...@wunderwood.org ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@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 arch...@mail-archive.com
