[TowerTalk] Ground Clamps

[Mark Spencer]

Interesting thread which brings to mind a question:
 
The last time I looked at the bronze clamps (purchased at Home depot) connecting my copper ground wire to my roof mounted galvanized steel antenna masts I noticed some minor discolouration and a white powdered material at the junctions between the copper wire and the bronze clamp and the bronze clamp and the galvanized steel mast.   The copper is not in direct contact with the galvanized steel.
 
I have put a clamp on ammeter on the ground wire and can't measure any current flowing thru the ground wire (I did not expect to see any, but I thought that if current was flowing thru the ground wire this might have explained what I was seeing.   As the ground wire is ultimatley tied into the electrical service ground and the some of the masts are connected via antenna mounts to coax shields that run back to radios in the shack I felt there was small possibility of current flowing thru the ground system.)
 
Given that the masts are roof mounted they are probably more exposed to the elements than clamps at ground level on a typical tower would be.  I'm not really worried about this but I did not expect to see visible corrision (if that is in fact what I am seeing ?) when using bronze clamps.    The next time I'm visiting comerical radio sites thru work I'll take a closer look at the ground clamps and see if notice any thing similar but I don't recall seeing this before.
 
Any comments would be welcome.


--- On Mon, 7/7/08, Alan NV8A <nv8a at att.net> wrote:

From: Alan NV8A <nv8a at att.net>
Subject: Re: [TowerTalk] Ground Clamps
To: "towertalk reflector" <towertalk at contesting.com>
Cc: "Roy & Peggy Bonvillian" <wd5dbv at bellsouth.net>
Received: Monday, July 7, 2008, 6:55 PM

On 07/07/08 05:37 pm Roy & Peggy Bonvillian wrote:

> I have just set my base for my 55G and have my UFER ground wires that need

> to be connected to the legs of the tower. I have 3 #4 gauge wire coming
out 
> of the cement near each leg. My question is where do I fine the proper 
> clamps to connect the bare copper wire to the 3 legs and also have a place

> to tie in the wire leaving each leg going out to the ground rods?


I've read that copper in contact with zinc (galvanized) is a no-no.
I've 
done as suggested by Polyphaser (although not always using their 
products): I've used stainless steel strips (cannibalized from s/s hose 
clamps) between the copper and the zinc. Using bronze clamps.

73

Alan NV8A


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