Topband: Lazy U Antenna

[Henry G. Elwell, Jr.]

Now that the flurry of Inverted U antennas is over, let me
comment on the Lazy U for those that want a simple,
effective antenna for 160m without the fuss of radials. This
antenna was originally developed by G8ON, now deceased, and
published in the RSGB Bulletin of September 1957. His son,
Peter Chadwick, G3RZP, sent me a copy of the original
article.  Bob Eldridge, VE7BS, included the Lazy U as part
of his antenna article in the Sept. 86 issue of 73
magazine.  I published an article comparing it to the other
antennas used on 160m in the Winter 1992 issue of Comm.
Quarterly. So a lot has been written on it.

	In my case, a 250' length of wire runs 90 feet, five feet
above the ground, 80' runs vertically up a tree, and 90' is
run horizontally at the 80' level to another tree so the
upper wire is directly over the ground level 90' segment.
You see the letter U laying on its side; a Lazy U.  The
current node is at the center of the 80' vertical section,
and the radiation of the horizontal segments "cancel" each
other.  The resulting radiation pattern per EZNEC, is a
circle in the azimuth plane, and radiation centered in the
vertical plane at 22 degrees.  The antenna is fed by a pi
network at the ground end of the 90' section.

	The antenna produces a circular radiation pattern, with
vertical radiation centered at 55 degrees when used on 80m.
A voltage node  occurs at the center of the 80' section,
producing essentially two vertical half-waves in phase
operation.  EZNEC shows that the antenna will produce
acceptable vertical radiation patterns through the 30m band
if anyone wants a multiband vertical.

	I originally shunt fed my 80' tower with 36 quarter wave
radials around the base; it worked well.  Without going into
details, I modified antennas on the tower, and it was no
longer useful for a 160m vertical.  I did not want to go
through the laying of radials again, and went to the Lazy U
to escape the problem. There is ground loss due to the lower
segment, but not of the type due to ground current loss
associated with a quarter wave antenna.  It has proved very
effective, and it is very simple to erect.  Thought I should
put it on the reflector for information.

Regards, Henry N4UH



--
FAQ on WWW:               http://www.contesting.com/FAQ/topband
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com