Re: Surge / Ground / Lightning

On May 6, 2:42=A0am, w_tom <w_t...@[EMAIL PROTECTED]
> wrote:
> =A0 =A0This will address some of your questions only in summary.
=A0Detail=
s
> are provided in other posts.
>
> =A0 First, much of this stuff was learned by earliest 20th century
> hams. =A0They would disconnect their antenna, put the lead inside a
> mason jar, and still suffer radio damage. Even mason jars could not
> stop or block lightning.

I'd love to see a reference for this.   In that time frame, lightning
was already fairly well understood.  I find it hard to believe any ham
would try to use a mason jar in this way.  Sounds more like some urban
legend to me.



But then the antenna was earthed, then damage
> stopped. =A0It's just like Franklin's lightning rod (air terminal).
> Protection has always been about diverting "it to ground, where it can
> do no harm". =A0Disconnecting did not provide sufficient protection.
> That wire had to be earthed.
>
> =A0 Protection for the TV, computer, and all other appliances is same.
> Computers contain some of the most robust protection. =A0Computer grade
> UPSes can output electricity so dirty (when in battery backup mode) as
> to even harm some small electric motors. =A0But computers are so robust
> as to make even that 'dirty' electricity irrelevant. =A0Do not assume
> computers have less internal protection. =A0Intel ATX standards require
> computers to be more robust than what is standard for other
> appliances.
>

And guess what component is used as part of that robust protection?
MOVs, which W_ denies are used in electronics/appliances.  Once again,
I'll ask the same question W_ refuses to answer.   How is it that MOVs
or any other component can offer protection when used in a PC power
supply, but are useless in a plug-in surge protector?    According to
W_, surge protection is impossible unless there is a direct and short
connection to earth ground.   Does the PC power supply come with a
built-in earth ground?