On 8/2/2011 1:37 PM, Dave Platt wrote:
You have a point Mark. I agree that a simple 1/4 wave groundplane is more
study and very easy to make using an so-239 and some piano wire. Steel wire
can be soldered right into the back, four bolts with nuts and four more
peaces of wire around 19" long with a bit of a downward bend and you have a
very good antenna.

It's worth noting that you don't actually need four radials. Two
radials (on opposite sides of the feedpoint, bent down at around 45
degrees) will produce a perfectly satisfactory ground-plane. The
patterns of 2- and 4-radial ground plane antennas are almost
indistinguishable. A 4-radial antenna may *look* as if it would
produce a much more circular pattern than a 2-radial antenna, but this
doesn't turn out to actually be the case.


That's true as far as the pattern. But.. The more radials you
use, the better the decoupling from the feed line. Most of my
1/4 wave GP's actually use 6-8 radials. I've done tests, and
it does make a difference. But for casual use, what you say is
true. Only two radials are required to get a pretty good omni
pattern. Or one, if vertical.. But then you might as well call
it a 1/2 wave vertical instead of a ground plane.
And you will then require some kind of decoupling scheme below
the vertical for optimum results. I prefer radial sets, cones, etc
vs feed line chokes.