[OZAPRS] rf earth

[Ray Wells]

Paul, et al,

The experience that Paul and I bring to the forum highlight the 
different thinking and experience of well-experienced individuals.

There are as many differences as there are similarities with RF, 
electrical and lightning protection earthing, which takes us back to a 
previous suggestion of mine, SIAS.

There is no one size fits all solution. Some will argue for a particular 
lightning protection scheme for a base site and others will attest to a 
catastrophic failure when using that scheme. A ground plane with most of 
most elements missing because of a direct hit is convincing evidence 
that the "correct" procedures don't always work. There is nothing to 
protect against a direct strike.

Unlike lightning and electrical earthing, RF also involves resonant 
lengths that can render an installation ineffective.

Do what you can within your resources, but remember, safety first. If 
you don't know, ask. To quote a saying from the broadcasting industry, 
if in doubt, don't.

Paul, thanks for your considered contribution.

Ray vk2tv


Paul Mullins wrote:
> Hi all,
> I know when I was emailing the 'big talk' on earthing systems.
> I did say to keep them separate, well in a nut shell it is almost impossible
> to do so, even here at my own home the two earths get tied together within
> the power supply, in the pdfs I have read regarding this very interesting
> subject to do or not to do.
>
> Ground loops can and will drive you nuts!
>
> I think maybe the better way to tie the two earths together might be using a
> very large inductive coil, maybe some thing that could carry 20 amps? And
> place this between the mains earth and the rf earth this way the two from a
> technical point of view are as one, but with a twist and coil to allow
> spikes? I am only thinking out loud here.
>
> I have been a licensed electrician for over 23 years and earthing is a
> subject that is not really taught but learnt over many years.
>
> A RF earth is best though as a high voltage substation earthing system.
>
> It comes down to what you need / want and what you can physically do.
>
> People that are going to do it them self invest in a good meter and test
> every connection point.
>
> BEST WAY TO SAY ALIVE, TREAT EVERY CABLE AS IT IS ALIVE, THEN YOU WILL STAY
> ALIVE!!
>
>
> Cheers
>
> Paul  
>
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