On Thu, 14 Feb 2008 14:28:47 -0200, Beat Meier wrote:
1) In general, ALL grounds must be bonded together for lightning
protection.
See http://audiosystemsgroup.com/SurgeXPowerGround.pdf
2) A connection to earth does not make an antenna work better,
but it does make it safer.
3) Some antennas (most verticals) DO work against a radial system
or counterpoise that accepts antenna current and interacts with
the near electric and magnetic fields of the antenna. Those
radials or counterpoise do NOT need a connection to earth.
4) The radio waves produced by the electromagnetic field from the
antenna DO interact with the earth in at least two ways. First,
they are reflected from the earth in the far field, and that
reflection is a major contribution to the vertical radiation
pattern of the antenna. Second, what we call "ground wave"
propagation is an interaction of the wavefront with the earth.
NEITHER OF THESE MECHANISMS USE A CONNECTION WITH THE EARTH.
Bottom line: An earth connection is very important for SAFETY.
That's ALL! And in general, all earth connections must be bonded
together for SAFETY.
73,
Jim Brown K9YC
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