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 arch...@mail-archive.com
