I believe Don is essentially correct regarding bonding all earth
terminals directly to the service entrance ground connection. This,
however, can be difficult and very costly in the case of an earth
terminal far from the service entrance. I believe that the NEC has
provisions for such cases [e.g. a barn or other outbuilding located some
distance from the service entrance].
200 ft sticks in my mind, but don't bet your paycheck on that.
Unfortunately, my copy of the NEC is located in an unknown box out of
many in the garage after our move. It is at least a decade old. It
will likely remain there.
Possibly someone who actually knows can enlighten the rest of us. It
*IS* a real issue.
73,
Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn
On 4/5/2017 2:05 PM, Don Wilhelm wrote:
Randy,
The RF does not need a ground other than the obvious connection to
your radial connection point.
I would dispense with the "unun" and connect the antenna wire and
radial connection point directly to your tuner. A few feet of wire
from your tuner to those points will not make a big difference since
your antenna is not resonant.
The only reason I can think of to connect your tuner to "station
ground" is for lightning protection. While that is a consideration
not to be taken lightly, be aware that *all* ground rods must be
connected by heavy wire to the utility entrance ground rod. That
heavy wire is #6 bare copper but #4 is preferred. That connection is
for AC mains safety, not for lightning protection or anything having
to do with RF.
The concept for lightning protection is to spread as much of the
charge as possible over as large an area of the earth as is possible.
Your radial system will help do that *if* the wires are large enough
to withstand the surge without evaporating the copper.
73,
Don W3FPR
On 4/5/2017 2:19 PM, Randy Cook wrote:
Weather damage repair time. I am rewiring my ~84 foot inverted L
antenna system, Up a SpiderPole about 31 feet, out about 53
additional feet. Still tuning length.
I have mounted a remote MFJ tuner on a post about 3 feet from the
antenna base. Antenna wire goes down the pole, connects to 4:1 Unun
input lug, then goes via coax to tuner. Out of the tuner to a long
coax run to my shack. Choke at the rig end of the coax run.
Radials mount on ground connection lug on the Unun.
I was a bit confused with the tuner wiring. The manual says to
connect ground lug to the ‘system ground’, I assume that means the
radial collection point. But, isn’t the tuner already connected to
the ‘system ground’ via the coax shield? Is it necessary to run
another wire from the tuner ground to the radial connection ground?
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to k6...@foothill.net
---
This email has been checked for viruses by AVG.
http://www.avg.com
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
