In article ,
"Birderman" wrote:
Hi,
As a newbie I would like to know when grounding why is it not
feasible to use a connection to the mains electricity supply to the
equipment. After all this is a sure way to make sure that everything
is connected to a common ground.
The mains electricity ground most of the time is to long electrically at
short wave frequencies. All conductors have an electrical property
called inductance determined by its length over its cross sectional
area. The ground wire in the cabling of just a few feet will be so
reactive to short wave frequencies as to cause the ground to appear not
to be connected on the other end of the wire due to its small cross
sectional area. The effect gets worse at higher frequencies.
Another reason is most electrical devices conduct noise currents to
ground using this wire so it will end up generating noise in your
receiver.
Some books say use water pipes and others say don't, very confusing
for a beginner, any comments on to the best approach.
If you are going to use a water pipe make it the one leading out of the
house into the ground as long as it is metal. Your best bet usually is
to have a separate ground system for the radio.
What about Ground Plane is that possible with a longwire antenna ?
There is a property of soil called ground conductivity. If itıs good at
the antenna location you can just use one or two ground rods but if its
poor you would have to connect wires to the ground rod placed on or in
the ground under the antenna.
A good ground plane for the long wire would be another wire under it on
the ground.
Why does the grounding stake need to be far away from the house, what
would a typical distance be to be considered far.
You want to get it away from the electrical service supply ground so all
the noise in that system doesnıt get into the radio input.
Depends on the ground conductivity but I expect that to translate to
several tens of feet at least.
Can the cable to the grounding stake be routed in the ground ?
Yes.
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Telamon
Ventura, California
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