Apropos of this, I use 1 inch OD soft copper refrigeration tubing for my
ground connections also. It is quite available and (relatively)
inexpensive. I order rolls of it from McMaster Carr, but your local
refrigeration shop will have it too.
In my case I also permanently attach the tubing directly to the grounding
points in question, (welding) and make runs as short as possible.
For example, the main RF ground is just outside my (separate) shack
building, and almost directly under it. My tubing runs from the single
point ground bar located 4 inches behind my rig on the wall, and goes
straight down through the floor to the outside ground point. Maybe 3.5 feet
total length. There is also an outdoor grounding connection plate located
right there just above the dirt, through which coax cables are brought and
thus bonded to ground. Those can also be disconnected outdoors, on the
"shack side" of this plate.
The outside RF "central" ground I have constructed is then bonded (outside)
to all my other grounds, including power system, telephone and cable system,
the grounds at the base of the tower, the grounds at the base of the
vertical and so forth and so on. None of that comes indoors. All of these
bonds are either refrigeration tubing, or for the longer runs, very heavy
copper wire. Of course these bonds are safety bonds only.
My RF ground refrigeration tube, being 3.5 feet long is barely more than 1
meter in length (obviously) which makes it an excellent performer. Useful
even on the 10 meter band, where it is still only very roughly 0.1
73 de Gary, AA2IZ
----- Original Message -----
From: "Bob McGraw - K4TAX" <RMcGraw@Blomand.net>
To: <Gary@doctorgary.net>; "Discussion of Ten-Tec Equipment"
Sent: Monday, April 06, 2009 10:23 AM
Subject: Re: [TenTec] RF Ground
> Here's what Jerry had to say and I agree:
> If you really want lightning and RF grounding, those ground sources need
> to be connected together with wide copper strap. 18" is a nice width.
> Otherwise the inductance is too much to be totally effective.
> 73, Jerry, K0CQ
> end quote:
> The 18" copper strap that Jerry suggests would be nice but would also be a
> nice investment today.
> In my case I use a piece of 1/2" copper refrigeration tubing to
> [actually via CAD WELD} all of my driven grounds. There's 3 at the base
> the tower in a ring and 1 at each corner of the house. The house has a
> series of lightning rods across the top. All of these points are
> together. Also, the mast out the top of the tower has 2 bonding flexible
> straps between the mast and the tower sleeve. This assures that the mast
> bonded to the tower and the path is not through my rotor.
> Yes, in your case, the path between your service ground and your antenna
> ground is through your station equipment via the coax. Not good!
> Bob, K4TAX
> ----- Original Message -----
> From: "Gary Smith" <Gary@doctorgary.net>
> To: "Discussion of Ten-Tec Equipment" <email@example.com>
> Sent: Monday, April 06, 2009 5:05 AM
> Subject: Re: [TenTec] RF Ground
>> Hi Bob,
>> My antennae use the same radial field of 60 or so 130' radials. The
>> radial plate is 360' from the house. The only connection between the
>> house and the radial field is via the coax shield. Are you suggesting
>> I run a length of additional wire from one of the radials to the
>> grounding point of the service entrance ground rod?
>> Gary, KA1J
>>> As to having a RF ground, a ground radial system below your antenna is
>>> reference point for that antenna. Several antennas can share the same
>>> radial system. Also that radial system must be bonded back to the
>>> entrance ground.
>>> Bob, K4TAX
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