>I am force to have my shack (HF & VHF) loacted on the second floor on a 2
>story house. MY water pipes are a mix of copper and PVC, and I am
>looking for the best method to provide a good ground system.
>I have purchased some of the copper foil (Gordon West stuff), but if I
>run that from my shack to an earth ground outside, it will probably be a
>50-60 foot run. Is this ok, or is there a better way to do this?
>I am very concerned about creating TVI / RFI, plus I want to have the
>best ground possible under the circumstances. I would appreciate hearing
>from anyone with any suggestions / comments on the best way to approach
Ok, Herb, you aren't going to get a good RF ground connnection to
Earth in your situation, but then no one does at VHF/UHF where a
1/4-wave is only 19 inches or less. An RF ground rarely does anything
for you in regard to TVI/RFI anyway (except sometimes making the problems
worse). You need to deal with that at the source, IE make sure your
transmitter doesn't emit any, and use balanced antennas that don't
need to work against Earth so that you won't have a "hot" shack.
The only reason you need an Earth connection is for lightning protection.
Since the bulk of lightning energy is under 2 MHz, a relatively long
run to Earth isn't much of a problem, as long as you keep the inductance
of the run low by avoiding sharp bends and the like, and practice single
point ground window technique where the cables enter the shack.
If your HF antenna is a vertical monopole, or a longwire, IE inherently
unbalanced with respect to Earth, then you may have some problems. If
you're using a ground mounted vertical, put your ground field under
*that*. If it's a longwire, you may need to run a counterpoise wire.
If you're using something balanced like a dipole or a beam, don't
worry about it. It doesn't need to work against Earth anyway.
Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | we break it. | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | |