I don't believe one could ever implement too much protection lightning
protection. At a minimum I recommend the following:
Tie all three grounding points together with low-impedance copper, either
1-1/2 inch strap or AWG 4 or larger. Use good quality mechanical
connections. A single-point ground system is what you're trying to achieve.
Ground your coax shield at both the top and bottom of the tower. Polyphaser
has hardware for doing this, although there have been homebrew methods
described on this list.
Use a good quality lightning arrestor on the coax at the entrance to the
shack. A copper ground panel inside the shack makes a very convenient
attachment point.
Ground the tower legs and interconnect all ground rods together with the
rest of your grounding system.
Don't forget to install suitable arrestors on other points of entry such as
power and telephone.
Good luck!
Wayne, WØZW
----- Original Message -----
From: "Bill Blake" <ka0vtg@yahoo.com>
To: <towertalk@contesting.com>
Sent: Sunday, November 20, 2005 5:42 AM
Subject: [TowerTalk] Antenna grounding and more
>A couple of questions for the group.. I have taken a few years away from
>the hobby and am just now getting back into it ( it's amazing what you
>forget) ...
>
> Ground rods: The distance between my tower and equipment ground will be
> 37.5 ft. I seem to remember something about ground loops (being bad) and
> if you count the A/C electrical ground I will have three grounding points
> around my house/ shack. Any comments or suggestions?
>
> Rohn 25G tower: I have acquired a 39' tower and plan on installing only
> a G5RV dipole at this time, according to the Rohn website I only need to
> guy at 40 ft and above. I realize that 39' is pushing the envelope but
> also assume that Rohn has several safety factors computed into the
> standard. With the minimal wind resistance of the dipole I am hoping that
> the tower will not need to be guyed any comments or suggestions? I have
> read several threads from hams that want to elevate the guy points and I
> do not want to try this..
>
> Lightning protection: Is a coax grounding point inside the shack enough
> or is more required at the tower or both? I live in the mid-west and we
> do tend to get several lightning storms a year and I would prefer to be
> able to keep my equipment working... How much protection is needed with
> out over killing the potential problem?
>
> Thank you in advance for your comments and help...
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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