> >An old AM broadcast engineer I know is also a ham and I
have chatted with
> >him on 80 meters... He uses a 1/4 wl. vertical antenna...
He has a 4 foot
> >square (4' x 4'), 10 ga., copper plate with a hole for
the base insulator
> >to pass through... He does not use radials... He gets
out just fine and
> >feels that the plate is not a compromise in gathering the
return currents
> >compared to the usual radial system that a city ham can
get down... He has
> >the room for some radials and states that changing to
the plate increased
> >his field strength over the previous radial system enough
that he no
> >longer uses radials...
> >I mention this as an item of interest for those who
cannot put out radials
> >that perhaps the cost of a copper plate may be a fair
return for
> >performance....
> >
> >He did state that thin copper sheathing as for roofs,
etc., is not as
> >efficient as a plate with some thickness of ~ 0.100" or
more - and that it
> >wants to be a single plate, or if pieced together should
be continuously
> >soldered at the joints......
>
> I would imagine that chap had good soil conductivity,
especially some
> distance away.
You can hear all kinds of things presented as fact, even
when they aren't.
Unless he lives in a saltwater pond the plate doesn't do
much over a handful of short radials the same length and
would never be high efficiency except perhaps on 6 or 10
meters.
My F series large pickup trucks are in the area of 15-20
ohms of ground loss resistance on 80 meters, and they are a
heck of a lot larger than 4ft by 4ft.
73 Tom
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