[ProAudio] AES on the west coast, was Re: Ampex/ProAudio List Dinner

[Bob Katz]

An important aside: The key to lightning protection is that the 
protector clamps the high voltage as closely as possible to the same 
reference point (possibly called "ground") as the circuit under 
protection. An actual earth ground is unnecessary and frankly, useless.

I have some Furse Ethernet protectors. The key is to connect the ground 
strap of the Ethernet protector to the circuit land of the ethernet 
circuit. That's as close as possible to the actual reference voltage 
("ground") of the active ethernet chips. I've soldered the ground strap 
directly to the metal ring around the CAT-x female. Works perfectly for 
lightning. If you run anything longer than a couple of inches over to a 
so-called "earth" or "u-ground" you just won't get any protection.

Some people have screwed that strap to an outlet screw or even to the 
chassis of an Ethernet Switch. FORGET ABOUT IT. It's no protection at 
all for high voltage lightning spikes.

Just proving once again that "earth" is a meaningless concept. How do 
you think they keep airplane electronics from burning out in lightning 
storms!

Bob


On 11/4/19 8:09 PM, Scott Dorsey wrote:

> A good introduction to lightning protection (which is not all there is
> to grounding, but is an important part of grounding and it is the thing
> most badly defeated by installing multiple grounding systems in one
> building) can be found at....
>
> http://www.panix.com/~kludge/LightningXprotectionXXgroundingXforXTelecommunications.pdf
>
> As far as I know the world record for bad grounding is held by the old
> 9:30 Club in Washington DC where more than 60 volts could be measured
> between two PE grounds.  This same institution may also hold the world
> record for filthiest restrooms.
> --scott
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-- 

If you want good sound on your album, come to Bob Katz 407-831-0233 
DIGITAL DOMAIN MASTERING STUDIO Author: *Mastering Audio* Digital Domain 
Website <https://www.digido.com/> No trees were killed in the sending of 
this message. However a large number of electrons were terribly 
inconvenienced.

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