The article is an AntenTop
Magazine variant of Chapter 7 from K3MT book ďHF Antenna Topics.Ē
got you down?† Neighbors
intimidating your tower plans?†
Need a really easy, portable HF antenna?†
Then the Grasswire may be the answer!† Virtually invisible, lightweight, and compact
(you can carry one in your hip pocket), this antenna works!† Iíve used one in various installations for
more than 10 years.
Read on - and listen
to the "experts" telling you that this is hogwash, that
an antenna like this can't work.†
But it does.† And
true experts, who have taken a decade or more to come to grips
with the intricacies of Maxwell's Math, know why.
Grasswires will not out-perform
a yagi, or a decent dipole up a half
wavelength.† Not in gain
or signal strength, at least.†
But they do survive ice and wind storms, and are practically
immune to lightning.† And they don't need a large tower or tall
support.† I deploy one from
my hip pocket at times - the balun to
match it is larger than the antenna!
- In Brief
is it?† Put simply, itís
an end-fed, longwire antenna that is laid right on the grass.† Hence the name.† Look familiar?† Yup!† Itís
a very low beverage antennaÖ
first Grasswire, built in the summer
of 1988 was just 204' of #22 AWG magnet wire laid along the propertyline, anywhere from 1"
to 6" above the ground.††
K3MT's HF ANTENNA TOPICS
For info on availability, please email to
shows plan and elevation views of a typical installation.
An 8' ground rod and
optional counterpoise wires are shown.†
The counterpoise is a 40í wire, center tapped.† Use it or the ground rod:† you donít need both.
These antennas are
largely resistive, with values ranging from 150 to 500 ohms or
so on average ground.† Iíve used them successfully on the soils northwest
of Washington, DC, on the sandy soils of the Cape Canaveral, Florida
area, in the rocky, shale soils of the
mountains in Somerset county,
PA, and on river bottomland of Allegheny County, PA.† One was used with great success by K3MT/VP9
in Southampton, Bermuda - the object of nightly pileups on 30
m CW for four nights.
Reflection and the Brewster
skeptic in you will doubt that such low antennas can work. After
all, its image in the ground radiates and cancels out all radiation.
True - if the ground is perfect. But nothing is perfect!