No, it is what it says, for static discharge. It won't prevent
strikes. Disconnect all cables before they enter your house and
ground them.

Ok thanks. Follow-up question then.......why do I want to get rid of the
static? What if I don't?
Thanks

On 13 Feb 2004 03:25:08 GMT, (Zeeeeeeee3) wrote:

No, it is what it says, for static discharge. It won't prevent
strikes. Disconnect all cables before they enter your house and
ground them.

Ok thanks. Follow-up question then.......why do I want to get rid of the
static? What if I don't?
Thanks

It might only take a static charge of a few hundred volts to damage
components in your radio. If you don't, that depends, most people
don't use them. Disconnect and ground your cables when storms are
heading your way.

The antenna requires an earth ground, first, as required by
National Electrical Code. That mounting rod should be
connected to an eight+ foot earth ground rod (available even
in Home Depot and Lowes). This required by NEC for human
safety, but also to protect transistors.

Incoming wire should enter building at the service entrance
so that a ground block (maybe $1 at Radio Shack or Home Depot)
connects 'less than 10 feet' to the building's single point
earth ground. Same earthing ground that also connects to AC
electric, telephone, and cable TV wire. Do not even think an
AC receptacle or water faucet will provide that necessary
earthing.

NEC requirements have changed since 1990 to require a
service entrance ground rod. You may need to install this
earth ground rod at the service entrance. Many homes don't
even have that much which is another reason why some homes
suffer household electronics damage.

Principles are demonstrated in this figure. Note an antenna
tower and building each have their own earth ground. Each is
earthed as if it were a separate structure. Every incoming
wire makes a connection to that earth ground. To make the
'system' work better, a ground wire interconnects the antenna
and building earth grounds:

http://services.erico.com/public/lib...es/tncr002.pdf

Static is irrelevant. A few hundred volts of static will
not damage any properly built radio. You could even static
shock your car radio antenna or a portable radio antenna
without damage. That would be as much as 18,000 volts - and
still no damage.

The earthing is required by NEC for human safety AND also
provides transistor safety. If lightning is provided a path
to earth ground via that exterior rod, then it too will not
seek earth ground, destructively, via your radio. Direct
strike lightning damage is that easily avoided.
Unfortunately, too many don't have necessary earthing, suffer
damage, and then declare nothing could have helped.
Generations of technical history say otherwise. Its all about
earthing - as even required by code.

Zeeeeeeee3 wrote:
Ok thanks. Follow-up question then.......why do I want to get rid
of the static? What if I don't?
Thanks

On Fri, 13 Feb 2004 14:41:50 -0500, w_tom wrote:

The antenna requires an earth ground, first, as required by
National Electrical Code. That mounting rod should be
connected to an eight+ foot earth ground rod (available even
in Home Depot and Lowes). This required by NEC for human
safety, but also to protect transistors.

Where in the NEC code does it say that you need an earth ground to
protect transistors?


Incoming wire should enter building at the service entrance
so that a ground block (maybe $1 at Radio Shack or Home Depot)
connects 'less than 10 feet' to the building's single point
earth ground. Same earthing ground that also connects to AC
electric, telephone, and cable TV wire. Do not even think an
AC receptacle or water faucet will provide that necessary
earthing.

NEC requirements have changed since 1990 to require a
service entrance ground rod. You may need to install this
earth ground rod at the service entrance. Many homes don't
even have that much which is another reason why some homes
suffer household electronics damage.

Principles are demonstrated in this figure. Note an antenna
tower and building each have their own earth ground. Each is
earthed as if it were a separate structure. Every incoming
wire makes a connection to that earth ground. To make the
'system' work better, a ground wire interconnects the antenna
and building earth grounds:


What figure?

Do you work for erico?

http://services.erico.com/public/lib...es/tncr002.pdf

Whats this link? Have one that works?



Static is irrelevant. A few hundred volts of static will
not damage any properly built radio. You could even static
shock your car radio antenna or a portable radio antenna
without damage. That would be as much as 18,000 volts - and
still no damage.

Sorry, static is not irrelevant. You need to read up on static damage
before you make such foolish posts. Every electronics manufacturer in
the world takes great lengths to control static. When you talk about
static shocking your car radio antenna, or portable radio antenna
without damage, you need to look at other paths that the static
electricity would be taking. Would you allow me to connect your CB
antenna connection of your radio directly to an A.C. line? Thats only
115 volts.


The earthing is required by NEC for human safety AND also
provides transistor safety. If lightning is provided a path
to earth ground via that exterior rod, then it too will not
seek earth ground, destructively, via your radio. Direct
strike lightning damage is that easily avoided.
Unfortunately, too many don't have necessary earthing, suffer
damage, and then declare nothing could have helped.
Generations of technical history say otherwise. Its all about
earthing - as even required by code.

Last time I read, current seeks all and any paths to ground. Has that
changed? Direct strike lightning damage isn't as easy as earth
grounding your antenna. Hopefully no one else will believe your B.S.
that all you need to do is earth ground your antenna and electrical
entrance box unless you are willing to pay for any damage that they
receive following your instructions.


Zeeeeeeee3 wrote:
Ok thanks. Follow-up question then.......why do I want to get rid
of the static? What if I don't?
Thanks

Manufacturer changed URL for that Technical Note again:
TN CR 002 The Need for Coordinated Protection

http://www.erico.com/public/library/...es/tncr002.pdf
This figure demonstrates how a radio can be protected even
from lightning strikes.

Static is irrelevant to radios because, as was posted
Every electronics manufacturer ... takes great lengths to
control static.
If static on an antenna was destructive to a radio, then every
time a human static discharges to that radio (many times
higher voltage), then the radio is damaged. But human static
discharge does not damage those JFETs. Internal protection
easily installed because static has such low current AND short
duration. Radio design assumes an antenna has been properly
earthed as even required by the NEC which therefore makes
internal protection effective.

Cell phone towers, 911 dispatcher radios, telephone
switching computers connected to overhead wires everywhere in
town. All must suffer direct strikes and not be damaged - as
was standard even before WWII. Why? Earthing, as described
in the below text, and demonstrated in that manufacturer's
figure makes protection even inside the radio effective.

If such earthing was not effective, then 911 emergency
dispatch and telephone operators would have to remove headsets
(stopped working) during every thunderstorm. They don't stop
working, do they. Protection so routine that it even makes
static electric discharge problems irrelevant and trivial by
comparison.

OPs antenna and antenna lead must connect as demonstrated by
that industry professional's technical note. For that matter,
visit this and many other 'real world' manufacturers whose
products are also effective because they discuss the most
critical component - earthing.


Lancer wrote:
On Fri, 13 Feb 2004 14:41:50 -0500, w_tom wrote:
The antenna requires an earth ground, first, as required by
National Electrical Code. That mounting rod should be
connected to an eight+ foot earth ground rod (available even
in Home Depot and Lowes). This required by NEC for human
safety, but also to protect transistors.

Incoming wire should enter building at the service entrance
so that a ground block (maybe $1 at Radio Shack or Home Depot)
connects 'less than 10 feet' to the building's single point
earth ground. Same earthing ground that also connects to AC
electric, telephone, and cable TV wire. Do not even think an
AC receptacle or water faucet will provide that necessary
earthing.

NEC requirements have changed since 1990 to require a
service entrance ground rod. You may need to install this
earth ground rod at the service entrance. Many homes don't
even have that much which is another reason why some homes
suffer household electronics damage.

Principles are demonstrated in this figure. Note an antenna
tower and building each have their own earth ground. Each is
earthed as if it were a separate structure. Every incoming
wire makes a connection to that earth ground. To make the
'system' work better, a ground wire interconnects the antenna
and building earth grounds:

Static is irrelevant. A few hundred volts of static will
not damage any properly built radio. You could even static
shock your car radio antenna or a portable radio antenna
without damage. That would be as much as 18,000 volts - and
still no damage.

The earthing is required by NEC for human safety AND also
provides transistor safety. If lightning is provided a path
to earth ground via that exterior rod, then it too will not
seek earth ground, destructively, via your radio. Direct
strike lightning damage is that easily avoided.
Unfortunately, too many don't have necessary earthing, suffer
damage, and then declare nothing could have helped.
Generations of technical history say otherwise. Its all about
earthing - as even required by code.

In , w_tom wrote:

......Same earthing ground that also connects to AC
electric, telephone, and cable TV wire.....
snip
......... Note an antenna
tower and building each have their own earth ground. Each is
earthed as if it were a separate structure. Every incoming
wire makes a connection to that earth ground. To make the
'system' work better, a ground wire interconnects the antenna
and building earth grounds:


........BAD idea. Tying your ground rods together makes a ground loop, which is
deadly for radio equipment. Use a completely -seperate- ground system for your
radio. Sink a ground rod where the coax enters the shack, tie the coax shield
directly to this rod (don't forget to waterproof the connection), and run your
ground strap and coax as close together as possible. Here's a diagram:

http://www.aimcomm.net/sparky/ground.gif

DON'T rely on your coax shield for a ground strap!!! You can braid a heavy-duty
strap using old power cords and it shouldn't cost you more than a few dollars at
the local thrift shop.

If AC noise becomes a problem, rewire the AC outlets used by the radio so their
ground goes to the new ground rod via the ground strap. Do NOT connect the
neutral (white) wire to this ground!


http://services.erico.com/public/lib...es/tncr002.pdf


Page has moved. Update your link.


Static is irrelevant. A few hundred volts of static will
not damage any properly built radio. You could even static
shock your car radio antenna or a portable radio antenna
without damage. That would be as much as 18,000 volts - and
still no damage.


Many radios aren't built "properly", and most modern radios use JFET or MOSFET
frontends, which are VERY suseptible to damage from static, even from potentials
as low as 50 volts (the breakdown potential of the protection diodes). That's
not the only problem -- static buildup on the antenna causes horrific noise!
Fortunately, the best solution is an easy one: shunt the center conductor of
your coax to ground with an RF choke, something on the order of 1 milliHenry or
larger (even an audio or power supply choke will work). Locate the choke at the
grounding block (see diagram) as any lightning strike will travel through that
choke and you don't want it inside the shack when that happens. On the upside,
it makes a beautiful blob of copper and iron that you could probably sell on
ebay for a decent price (after the smell goes away, of course).


The earthing is required by NEC for human safety AND also
provides transistor safety. If lightning is provided a path
to earth ground via that exterior rod, then it too will not
seek earth ground, destructively, via your radio. Direct
strike lightning damage is that easily avoided.


Wrong. If the coax is plugged into the radio when lightning hits the antenna,
it's safe to assume that your radio will fry. Period. Doesn't matter how much
protection you have. Why? Because lightning packs a few million volts (not an
exaggeration) and will jump just about any gap to ground. But gaps are also
resistors, and since lighting also carries a few million amps (again, not an
exaggeration), you are going to have a SIGNIFICANT voltage potential on your
coax. In fact, the potential and current are so high that the core insulation
breaks down for the full length of the coax and it is literally cooked from end
to end. I've seen it more than once. And that's WITH proper grounding!

Unplug the coax from the radio when not in use. If you want to use a "device",
get one of those big blade switches so there is a big gap, and wire it so the
antenna is shorted to ground when not connected to the radio.


Unfortunately, too many don't have necessary earthing, suffer
damage, and then declare nothing could have helped.
Generations of technical history say otherwise. Its all about
earthing - as even required by code.


Get some field experience. THEN come here and talk about lightning protection.








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http://www.astrosurf.com/lombry/qsl-...protection.htm

This site has some good info.

Actually that astrosurf.com author misses the point. He
cites a benchmark in surge protection, then assumes the surge
protector (or more of them) provides protection. Even
Polyphaser does not make that claim. Far better information
are the legendary application notes from Polyphaser. Do they
discuss their products? Of course not. Polyphaser discusses
THE protection - earthing.

Making a short connection to earth is so critical that
Polyphaser even makes protectors with NO connection. Instead
the protector mounts directly ON earth ground. Polyphaser
application notes are at:
http://www.polyphaser.com/ppc_pen_home.asp

Why did the author suffer damage? Every damaged item was
part of a circuit from cloud to earth. Only damaged were
items that completed a path to earth.

BTW, those manufacturers who discuss earthing make serious
protectors. Visit their product line appreciate what serious
protector products are.

Randy wrote:
http://www.astrosurf.com/lombry/qsl-...protection.htm

This site has some good info.

Unfortunately Frank Gilliland has exaggerated his numbers
due to insufficient experience and too much time listening to
myths. His numbers will be exposed as fiction.

Field experience says repeatedly that antenna and radio can
suffer direct strikes without damage. That is proven about 25
times every year atop Empire State Building since the 1930s.
According to Frank, they must suffer damage 25 times per
year. Let's start with his numbers.

Millions of volts? Yes. But same voltage does not appear
everywhere in a circuit - basic circuit theory. Those
millions of voltage are in the sky. Surge protection is about
making those millions of voltage appear elsewhere which is why
industry professionals discuss impedance. A low impedance
connection to earth means no millions of volts.

Millions of amps? Only in dreams. Most lightning is below
20,000 amps and of such short duration as to not be high
energy. Lightning typically so low energy at the strike
location (not to be confused with what is miles above) that
well over 90% of all trees struck leave no indication of that
strike.

How big need a wire be to shunt (earth) lightning? Even the
US Army training manual TM5-690 requires 10 AWG wire to
conduct the direct lightning strike without damage. Same wire
found in 20 or 30 amp AC electric boxes because lightning is
not the millions of amps so often claimed in urban myths.
Unlike Frank, numbers are provided by multiple, reliable
sources.

Another who does this for a living:
From Colin Baliss "Transmission & Distribution Electrical
Engineering":
Although lightning strikes have impressive voltage and current values
(typically hundreds to thousands of kV and 10-100 kA) the energy
content of the discharge is relatively low ...

or Martin A Uman in All About Lightning
Most of the energy available to the lightning is converted along
the lightning channel to thunder, heat, light, and radio waves,
leaving only a fraction available at the channel base for
immediate use or storage.

In short, Frank Gilliland's numbers are classic myths.


Pre WWII ham radio operators demonstrated what was required
for protection. First they would disconnect antenna and still
suffer damage. Then placed antenna lead in a mason jar, and
still suffered damage. But when antenna was connected to
earth ground, then no damage. Neither a mason jar nor "one
of those big blade switches" sufficiently blocks destructive
transients. Of course not. Lightning was not blocked by
miles of air. Is a mason jar or knife switch to do what miles
of air could not? Of course not. For no damage, provide the
destructive transient what it wants - earth ground.

zeeeeeeee's antenna installation is demonstrated by a
figure in TN CR 002 The Need for Coordinated Protection
(corrected URL)

http://www.erico.com/public/library/...es/tncr002.pdf

Need anyone suffer damage from direct lightning? Of course
not. Such damage is considered a human failure because proper
earthing is so effective and so inexpensive. Another
professional who makes that point in direct contradiction to
posted myths:
http://www.harvardrepeater.org/news/lightning.html
Well I assert, from personal and broadcast experience spanning
30 years, that you can design a system that will handle *direct
lightning strikes* on a routine basis. It takes some planning
and careful layout, but it's not hard, nor is it overly
expensive. At WXIA-TV, my other job, we take direct lightning
strikes nearly every time there's a thunderstorm. Our downtime
from such strikes is almost non-existant. The last time we went
down from a strike, it was due to a strike on the power company's
lines knocking *them* out, ...
Since my disasterous strike, I've been campaigning vigorously to
educate amateurs that you *can* avoid damage from direct strikes.
The belief that there's no protection from direct strike damage
is *myth*. ...
The keys to effective lightning protection are surprisingly
simple, and surprisingly less than obvious. Of course you *must*
have a single point ground system that eliminates all ground
loops. And you must present a low *impedance* path for the
energy to go. That's most generally a low *inductance* path
rather than just a low ohm DC path.

Important point. This professional did not say
'resistance'. He said 'impedance' which is why wire length is
so critical. 'Impedance' is why an incoming wire (antenna,
CATV, telephone) must first drop down to make a short
connection to earth before rising up to enter a building.
Just one of the "careful layout" techniques learned from
underlying theory tempered by decades of experience.

zeeeeeeee's tower requires earthing to meet human safety
requirements of National Electrical Code AND to provide
transistor safety. Earthing required twice over. Once
properly earthed, then even unplugging for protection would be
unnecessary - as has been demonstrated too many times at too
many locations since before WWII.


Frank Gilliland wrote:
In , w_tom wrote:
The earthing is required by NEC for human safety AND also
provides transistor safety. If lightning is provided a path
to earth ground via that exterior rod, then it too will not
seek earth ground, destructively, via your radio. Direct
strike lightning damage is that easily avoided.

Wrong. If the coax is plugged into the radio when lightning hits
the antenna, it's safe to assume that your radio will fry. Period.
Doesn't matter how much protection you have. Why? Because lightning
packs a few million volts (not an exaggeration) and will jump just
about any gap to ground. But gaps are also resistors, and since
lighting also carries a few million amps (again, not an
exaggeration), you are going to have a SIGNIFICANT voltage
potential on your coax. In fact, the potential and current are so
high that the core insulation breaks down for the full length of
the coax and it is literally cooked from end to end. I've seen it
more than once. And that's WITH proper grounding!

Unplug the coax from the radio when not in use. If you want to use
a "device", get one of those big blade switches so there is a big
gap, and wire it so the antenna is shorted to ground when not
connected to the radio.

"w_tom" wrote in message
...
Unfortunately Frank Gilliland has exaggerated his numbers
due to insufficient experience and too much time listening to
myths. His numbers will be exposed as fiction.

Field experience says repeatedly that antenna and radio can
suffer direct strikes without damage. That is proven about 25
times every year atop Empire State Building since the 1930s.
According to Frank, they must suffer damage 25 times per
year. Let's start with his numbers.

Millions of volts? Yes. But same voltage does not appear
everywhere in a circuit - basic circuit theory. Those
millions of voltage are in the sky. Surge protection is about
making those millions of voltage appear elsewhere which is why
industry professionals discuss impedance. A low impedance
connection to earth means no millions of volts.

Millions of amps? Only in dreams. Most lightning is below
20,000 amps and of such short duration as to not be high
energy. Lightning typically so low energy at the strike
location (not to be confused with what is miles above) that
well over 90% of all trees struck leave no indication of that
strike.

How big need a wire be to shunt (earth) lightning? Even the
US Army training manual TM5-690 requires 10 AWG wire to
conduct the direct lightning strike without damage. Same wire
found in 20 or 30 amp AC electric boxes because lightning is
not the millions of amps so often claimed in urban myths.
Unlike Frank, numbers are provided by multiple, reliable
sources.

Another who does this for a living:
From Colin Baliss "Transmission & Distribution Electrical
Engineering":
Although lightning strikes have impressive voltage and current values
(typically hundreds to thousands of kV and 10-100 kA) the energy
content of the discharge is relatively low ...

or Martin A Uman in All About Lightning
Most of the energy available to the lightning is converted along
the lightning channel to thunder, heat, light, and radio waves,
leaving only a fraction available at the channel base for
immediate use or storage.

In short, Frank Gilliland's numbers are classic myths.


Pre WWII ham radio operators demonstrated what was required
for protection. First they would disconnect antenna and still
suffer damage. Then placed antenna lead in a mason jar, and
still suffered damage. But when antenna was connected to
earth ground, then no damage. Neither a mason jar nor "one
of those big blade switches" sufficiently blocks destructive
transients. Of course not. Lightning was not blocked by
miles of air. Is a mason jar or knife switch to do what miles
of air could not? Of course not. For no damage, provide the
destructive transient what it wants - earth ground.

zeeeeeeee's antenna installation is demonstrated by a
figure in TN CR 002 The Need for Coordinated Protection
(corrected URL)

http://www.erico.com/public/library/...es/tncr002.pdf

Need anyone suffer damage from direct lightning? Of course
not. Such damage is considered a human failure because proper
earthing is so effective and so inexpensive.

So, you claim that ALL lightning strikes can be safely shunted to Earth,
with no damage along the path? Well, I don't have 30 years experience in the
electrical transmission and distribution industry, but I do have 25 years.
And I have seen properly earth grounded transmission and distribution poles
where the awg #6-#4 CU wires were mostly vaporized. Sure, there were bits
and short pieces left, but for the most part, the wire was gone. I confer
with you most of what you say, but you would be not completely honest to say
that all lightning strikes can be earthed with no damage. Possible? Maybe.
Practical? Nope.There will be strikes of magnitude where practical
techniques fail.