Topband: RFI - and lots of it

[Tom W8JI]

> Yes, or where other premises grounds are tied together. Systems like 
> Telco, CATV, satellite, even lightning rods if there are any, building 
> steel if there is any.
>

It doesn't matter where in the world we live, electrons all follow the same 
physical laws.
There are three things that should apply to advice:

1.) What really works and actually is a good thing to do
2.) What is a bad thing to do
3.) What still meets but safely works around local codes

The USA and Japan does some really stupid things with 12V radio systems, 
like negative lead fuses and power sources and radios with negative 12V 
rails tied to ground at both ends.

The UK is smarter on that, with requirements a mobile negative NEVER go to a 
battery negative post and never have a fuse. This should, through common 
sense, apply to a 12V supply on a desk 12V powered Ham radio. We are, 
however, locked in a loop of doing things the wrong way because that is how 
we do it.

The USA is good with the use of a common entrance point ground for 
everything, where all utilities like CATV, Telco, safety, and power have one 
single common "entrance" ground point, although that is sometimes missed. 
The ground rod means very little compared to the importance of the common 
bonding.

Our local fire station caught fire from a lighting strike because the fools 
they hired to do a wireless internet system just run cables in willy-nilly 
through plastic pipe because it "meets code". Occasionally they will have 
problems at different county buildings in storms because they have utter 
nonsense in the wiring, but it "meets code".  So far they have had a fire in 
a fire station (and destroyed much of the computer gear), lost the tag 
office, and lost things at the sheriff's dispatch system.

But the system that will keep burning up, and maybe eventually even kill 
someone, does meet code.  That is what matters.   :)

There is little that can ever be bad about using a single point ground, but 
adding a second path to ground (which no longer makes it single point) can 
quickly become a disaster.

It doesn't matter if we are in London or LA, electrons and grounds work the 
same way. The issue we face is making sure it works correctly, while not 
violating codes. Meeting codes is NOT a cure, and can cause a problem.

73 Tom