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Old July 2nd 08, 04:54 PM posted to rec.radio.amateur.antenna
K7ITM K7ITM is offline
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First recorded activity by RadioBanter: Jul 2006
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Default Open Wire fed lengths

On Jul 2, 8:08 am, John Smith wrote:
Cecil Moore wrote:
Ron Walters wrote:
Any recommended WEB sites or comments are welcomed.


If your ground wire is an appreciable percentage of
a wavelength, it is a radiating element grounded at
one end, i.e. not a ground. An artificial ground
might help to reduce RF in the shack.


If your antenna is balanced, you don't need an RF
ground.


Cecil:

Say I had a situation where I must use a ground wire which IS an
appreciable percentage of a wavelength ... and don't wish it to radiate.

Could I accomplish this by using coax as the ground-wire and choking the
outer braid by sufficient windings on a toroid core, and grounding the
center conductor and the braid to earth though good and deep grounding
spikes or wires?

Regards,
JS


The only way to keep a wire--e.g., piece of coax--from being a
radiator is to keep net current at zero. If there's no net current,
you didn't need the wire anyway (at that frequency, at least). If
it's a protective ground for mains frequency, it will probably still
work for that purpose if you add ferrite for RF choking.