On Sat,2/20/2016 12:59 PM, Gerald Wolczanski wrote:
What am I missing here? Every schematic I've seen of an end-fed wire
shows a ground symbol at the tuner. As all my equipment chassis are
connected (perhaps not "bonded") to a thick ground wire - that means the
tuner is as well.
That's the problem our predecessors created with the "ground" symbol and
using it to describe at least four different things. The answer to your
question requires more than a single paragraph, which is why I posted
the link to my tutorial on grounding and bonding.
http://k9yc.com/GroundingAndAudio.pdf
The short answer is long, but here are some key points. 1) BONDING and
SHIELDING are what prevent noise. That does NOT require a connection to
earth. 2) End-fed antennas do NOT require a connection to earth. What
they do need is a COUNTERPOISE, which can be a radial field. 3) The
counterpoise serves as a return for antenna current. 4) The earth is a
big resistor. If we shove current into it, it will burn (waste)
transmitter power. 5) If the counterpoise is a radial field, the radials
will SHIELD the antenna from the lossy earth. Antenna current flows in
GOOD conductors (radials) rather than lossy earth. SO -- what that
"ground" symbol really means is "counterpoise" or radials. 6) If you
don't give the antenna a "good" return path, it will use what you give
it. That could be a wire connected to lossy earth, or it could be the
green wire in your house. 7) Whatever return path you give it WILL
BECOME PART OF THE ANTENNA! That means it will RECEIVE NOISE if it's
close to noise sources. Most houses and neighborhoods are full of noise
sources. 8) We DO need an earth connection for lightning protection. 9)
We MUST bond together all grounded objects in our homes -- it's the LAW,
and is required for electrical safety. 10) The good news is that proper
grounding and bonding makes our systems work better, and makes them more
free from noise.
That's the short answer. Now study the tutorial that I took a month to
put together.
73, Jim K9YC
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