On 12/27/2011 3:47 PM, Cqtestk4xs@aol.com wrote:
> Anybody out there with some technical info on whether the grounding is
> necessary to keep the roof at the same potential to everything else.
Your exactly on target about keeping everything at the same potential.
Good engineering practice says bond all metal together and to ground.
Yes, I would definitely bond your metal roof.
> Also before I even got any towers up last summer, we got nailed with a
> lightning hit that came through the Direct TV and took out our 60 inch screen
> which was two days old. Any place to get a Polyphaser for this that won't
> break the bank? I believe Direct uses around 1.2 gHz.
I'd bet that the fundamental cause of your TV dying was either that
everything was not properly bonded together, or that you had MOVs on
one or more of the branch circuits in your system. The shield of your
Direct TV lead-in should be bonded to the power system ground, and the
telco ground, and your roof antenna ground, and your ham antenna
grounds, and all ground rods. As to MOVs -- the only safe place for an
MOV in a power system is at the service entrance.
As to a lightning arrestor -- look at my White Paper on power and
grounding for audio and video systems on my website for F-connector
arrestors I found.
73, Jim Brown K9YC
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