Two dipoles, 34 ft and 100 to 140 ft, each fed with ladderline
and run in the same direction, will give almost complete
coverage on the higher bands. The Longer dipole will act
as various types of long wire antennas on each of the higher
bands with 4 main lobes roughly 30 degrees from the wire
plus smaller and narrower lobes in between.
The short (20M dipole) will have a figure 8 pattern broadside
to the wire from 10 thru 30 Meters, filling in the nulls of the
longer antenna. Point the ends to low population centers
or put up some more dipoles to cover the end nulls.
This is exactly what I use on the WARC bands except that
I have 3 - 80M horizontal dipoles at 70, 90, and 140 ft. with
different orientations. My 20M dipole is at 50 ft. With
multiple (long) dipoles, you really can 'see' the various lobes
(and nulls).
Heights from 40 to 60 ft work VERY WELL on 10 thru 30M
especially if the antennas are in the clear and away from
metal objects or at least perpendicular to them.
Tom N4KG
On Sun, 2 Sep 2001 "Tom Rauch" <w8ji@akorn.net> writes:
>
> > My solution for my 50' x 100' lot is going to be an 88' dipole,
> with the feed at about 45' [if I ever get it up!]. The ends will be
> > between 25 & 30' up and will probably zig-zag somewhat. They will
> > also run more or less parallel and within 20 to 25 feet of a bunch
> of residential power lines... This will be fed with 300 ohm twin
> lead. I'm not expecting stellar performance, but it should get me
>on the air.
>
> That is an excellent system for a restricted lot, especially if you
> drop the feedline straight down to earth and put in a good ground
> system (or the best ground system you can do).
>
> You can cover all bands by tying the feeders together and using it
> as a vertical on 160 and 80, and a dipole on the other bands. The
> switching system can be very simple.
>
> I'd wager that antenna would blow away any other system you
> could fit in that area for low bands.
>
> 73, Tom W8JI
> W8JI@contesting.com
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 96 feet for under $1500!! http://www.anwireless.com
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|