On Thu, 09 Mar 2006 23:28:12 -0500, jawod wrote:

I know this has been addressed on the group before but I remain confused.

I will string a dipole in the trees. The coax shield will be earth
grounded, as well as the balun and lightening arrestor.

The BalUn? As for each, or the rest, where will that ground be? Back
in the shack? Out below the antenna?

Now, in the 2nd floor shack, I've read that running a ground line from
equipment 15 feet or more (in this case) to an earth ground will bring
RF into the shack and be a potent source for TVI, etc.

Poor choice of reading. It should have been extensive enough to
resolve your confusion.

My choice, then, is to use the ground on the mains.

Not always the best choice, but all such considerations have issues.

Given that the shield is earth grounded on the antenna and the equipment
is grounded to the mains, isn't this a good scenario for ground loop?

You better believe it.

Seems like a catch-22.

My own gut says safety first, lower risk of RF issues after-the-fact by
? what ?

You first have to figure out what ground means.

I remember suggestions of coiling the ground wire in an RF choke,
multiple ground lines of various lenghts to mess with harmonics.
Ferrite beads? Chicken blood and a black cat?

Hi John,

A dipole certainly doesn't need a ground connection. Neither does a
choke or BalUn. The lightning arrestor - obviously. But you are not
going to do that through house wiring.... are you? No. So where?

Starting with that last point, the ground needs to be close by the
arrestor, and given the coax can be laid out anywhere, it may as well
pass nearby your service ground where you can provide a short ground
lead to the arrestor.

Then follows the possibility of the ground loop. This will only arise
if the safety ground carries current (it shouldn't) or the neutral
return to that service ground does, and has some resistance to boot.
It stands to reason there will be current, what remains to be seen is
if there is appreciable resistance (a poor connection).

Try as you might to avoid it, you WILL have a ground connection to the
service ground from your rig (unless you are floating free on battery
power and have absolutely no other accessories going to your rig).
When you connect your arrestor to ground, this will guarantee a loop
configuration. Any potential (pun intended) problem is strictly a
matter of this resistance and current.

I'll cut it short with this as questions are sure to follow.

73's
Richard Clark, KB7QHC