From: Randall Rhea (email@example.com)
=> I'd just like to find out from you, which do you consider a better
=>antenna for working DX using QRP? A Horizontal dipole or vertical? What are
=>the related considerations, eg. height, length, ground etc etc.
It depends on your situation. In general, a horizontal antenna is
better for DX. It generally picks up less noise, and it generally
radiates your signal better for DX.
If you cannot install a horizontal antenna at least 1/4-wavelength
above the ground, then generally your signal will be radiated
straight up into the air, which can be bad for DX. Then it's time
to look at a vertical. I say "generally" a lot because it depends
on your location. For bands like 160m, where it is usually impossible
to install a horizontal antenna 1/4-wavelength above the ground, hams
use verticals for transmitting.
The problem with verticals is that they require extensive radial
systems for ground. For shorter wavelengths, (e.g. 10m, 15m, maybe 20m)
a ground plane provides a good ground, but a hortizontal will work better
for these bands. For 40m, a number of hams use verticals, even shorted
verticals with big "top hats", but they use a lot of radials. There are
some manufacturers that sell "no radial", "shortened" antennas for HF,
but don't expect to get any performance from them, especially for QRP.
Think of the Earth as a big sponge that soaks up your signal if you
don't have a good radial system.
I sometimes use a random length wire attached to an antenna tuner
thrown up into a tree. I also use a 1/4-wave wire attached to the ground
terminal of the tuner for each band I work. This is a nice, multi-band,
portable "vertical" antenna. It does not work as well as a dipole,
but it's easy to carry around an install.
Randall Rhea Informix Software, Inc.
Project Manager, MIS Sales/Marketing Systems firstname.lastname@example.org
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