P
Poxy
Guest
The subject says it all - is this something that is often/ever done?
T
Trevor Wilson
Guest
"Poxy" <pox@poxymail.com> wrote in message
news
A05e.2528$5F3.1863@news-server.bigpond.net.au...
Seriously, there is not much you can do. When my antenna guy put mine up, he
offered me lightning protection. For $150.00, I figured it was cheap
insurance. He put a 7mm diameter aluminium cable from the mast to ground. It
probably doesn't work, but it is probably better than nothing. In 30 years,
I've not had a problem, but that proves very little.
--
Trevor Wilson
www.rageaudio.com.au
news
A05e.2528$5F3.1863@news-server.bigpond.net.au...**Pray.
Seriously, there is not much you can do. When my antenna guy put mine up, he
offered me lightning protection. For $150.00, I figured it was cheap
insurance. He put a 7mm diameter aluminium cable from the mast to ground. It
probably doesn't work, but it is probably better than nothing. In 30 years,
I've not had a problem, but that proves very little.
--
Trevor Wilson
www.rageaudio.com.au
D
David L. Jones
Guest
Poxy wrote:
Dave
The paranoid disconnect the cable from the wall.
Dave
M
Mark H
Guest
The answer is simple!
Install a 30mm steel pipe in the ground next to your house, just make sure
it's 3m higher than your antenna and at least 2m underground.
Of course, this may attract more lightning than you usually have hit your
aerial...
-mark
B
Brian Goldsmith
Guest
"Poxy" <pox@poxymail.com> wrote
The subject says it all - is this something that is often/ever done?
**** I have never seen any TV antenna fitted with a non translucent
cover.Then again I really dont understand why you want to keep the light
away from the antenna!!!!
Brian Goldsmith.
The subject says it all - is this something that is often/ever done?
**** I have never seen any TV antenna fitted with a non translucent
cover.Then again I really dont understand why you want to keep the light
away from the antenna!!!!
Brian Goldsmith.
J
Jim
Guest
"Brian Goldsmith" <brian.goldsmith@nospam.echo1.com.au> wrote in message
news:dj45e.2721$5F3.1394@news-server.bigpond.net.au...
300 ohm ribbon to blow a rather large hole in the concrete floor. I've been
a bit sus of bright flashes and loud bangs ever since .
news:dj45e.2721$5F3.1394@news-server.bigpond.net.au...
to be high. LightNing hit next doors' aerial and ran down the disconnected
300 ohm ribbon to blow a rather large hole in the concrete floor. I've been
a bit sus of bright flashes and loud bangs ever since .
C
Caliban
Guest
Poxy wrote:
It's a bit tricky to substantially earth the screen on RG59 though.
One of these might be the go:
http://www.novaris.com.au/images/stories/Sales%20Kit/SK05/CB12-90_high.pdf
http://www.novaris.com.au/images/stories/Sales%20Kit/SK05/pp10_high.pdf
conductors and earthing the cable screen is about all you can do.
It's a bit tricky to substantially earth the screen on RG59 though.
One of these might be the go:
http://www.novaris.com.au/images/stories/Sales%20Kit/SK05/CB12-90_high.pdf
http://www.novaris.com.au/images/stories/Sales%20Kit/SK05/pp10_high.pdf
D
dmm
Guest
On Thu, 07 Apr 2005 02:06:13 GMT, "Poxy" <pox@poxymail.com> wrote:
Lightning strikes happen quite often in the tropics, so its only a good
idea to incorporate them in your system if that's your location AND you are
prepared to put up with the expense. BUT you (preferably an expert) would
have to design the system to accomodate the very high currents that would
occur in the event of a direct lightning strike. A very large solid copper strap
(say 75mm wide by 3mm thick) and short, would have to connect the shield
connection of the protection device to a very good ground, say a 2 metre solid
copper rod belted into the ground at the coax entry point, where the protection
device is located. No braids. Most people would simply increase their insurance and
put up with the inconvenience of a dead tv, and having to replace the antenna
and coax occasionally. If you're not in high lightning strike zone, you might as
well chance it, like the rest of us.
Darwin and on Bathurst Island a few years ago. Very expensive though.
Lightning strikes happen quite often in the tropics, so its only a good
idea to incorporate them in your system if that's your location AND you are
prepared to put up with the expense. BUT you (preferably an expert) would
have to design the system to accomodate the very high currents that would
occur in the event of a direct lightning strike. A very large solid copper strap
(say 75mm wide by 3mm thick) and short, would have to connect the shield
connection of the protection device to a very good ground, say a 2 metre solid
copper rod belted into the ground at the coax entry point, where the protection
device is located. No braids. Most people would simply increase their insurance and
put up with the inconvenience of a dead tv, and having to replace the antenna
and coax occasionally. If you're not in high lightning strike zone, you might as
well chance it, like the rest of us.
P
Poxy
Guest
Thanks for the answers - I kind of suspected that remotely effective
lightning (see, I can spell, somtimes) protection was a big ask for an
antenna, but after a TV got fried by a strike, I thought I should check...
lightning (see, I can spell, somtimes) protection was a big ask for an
antenna, but after a TV got fried by a strike, I thought I should check...
F
Franc Zabkar
Guest
On 6 Apr 2005 19:38:30 -0700, "David L. Jones" <altzone@gmail.com> put
finger to keyboard and composed:
equipment on the last occasion. His neighbour was worse off - his
meter box had to be replaced. Fortunately my friend was insured.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
finger to keyboard and composed:
A friend's house has been hit twice. He lost most of his electronicPoxy wrote:
The subject says it all - is this something that is often/ever done?
The paranoid disconnect the cable from the wall.
Dave
equipment on the last occasion. His neighbour was worse off - his
meter box had to be replaced. Fortunately my friend was insured.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
B
Bodgey
Guest
That's from the lightening hitting his power supply not the aerial. Most
lightening hits come from the power supply, being hit on your aerial is very
unlikely.
"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:dm9b51lvj5qf1636tfrdnlvh9g6rbb4sgh@4ax.com...
lightening hits come from the power supply, being hit on your aerial is very
unlikely.
"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:dm9b51lvj5qf1636tfrdnlvh9g6rbb4sgh@4ax.com...
On 6 Apr 2005 19:38:30 -0700, "David L. Jones" <altzone@gmail.com> put
finger to keyboard and composed:
Poxy wrote:
The subject says it all - is this something that is often/ever done?
The paranoid disconnect the cable from the wall.
Dave
A friend's house has been hit twice. He lost most of his electronic
equipment on the last occasion. His neighbour was worse off - his
meter box had to be replaced. Fortunately my friend was insured.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
B
Brian Goldsmith
Guest
"Bodgey" <ihate@spam.com> wrote
That's from the lightening hitting his power supply not the aerial. Most
lightening hits come from the power supply, being hit on your aerial is very
unlikely.
***** The mind boggles!!!!!!!!!
Brian Goldsmith.
That's from the lightening hitting his power supply not the aerial. Most
lightening hits come from the power supply, being hit on your aerial is very
unlikely.
***** The mind boggles!!!!!!!!!
Brian Goldsmith.
M
Michael A. Terrell
Guest
Bodgey wrote:
Really? Why did I find pieces of my TV antenna more than 150 feet
from the mast after it exploded from a lightning strike? The same
strike burnt open the underground phone line for more than a mile out to
the highway where it destroyed the electronics in the phone companies
pedestal? it also damaged a computer and monitor that had no cables
connected when lightning hit the antenna. Over $2000 dollars worth of
damage including battery powered items that had IC chips explode from
the EMP.
--
Former professional electron wrangler.
Michael A. Terrell
Central Florida
Really? Why did I find pieces of my TV antenna more than 150 feet
from the mast after it exploded from a lightning strike? The same
strike burnt open the underground phone line for more than a mile out to
the highway where it destroyed the electronics in the phone companies
pedestal? it also damaged a computer and monitor that had no cables
connected when lightning hit the antenna. Over $2000 dollars worth of
damage including battery powered items that had IC chips explode from
the EMP.
--
Former professional electron wrangler.
Michael A. Terrell
Central Florida
F
Franc Zabkar
Guest
On Sat, 09 Apr 2005 21:33:02 GMT, "Bodgey" <ihate@spam.com> put finger
to keyboard and composed:
good reason to be paranoid. In fact another friend's house (at a
different location) has also been hit more than once. His strikes came
via the power supply, too.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
to keyboard and composed:
I agree. I was just making the observation that some people have a
good reason to be paranoid. In fact another friend's house (at a
different location) has also been hit more than once. His strikes came
via the power supply, too.
"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:dm9b51lvj5qf1636tfrdnlvh9g6rbb4sgh@4ax.com...
On 6 Apr 2005 19:38:30 -0700, "David L. Jones" <altzone@gmail.com> put
finger to keyboard and composed:
Poxy wrote:
The subject says it all - is this something that is often/ever done?
The paranoid disconnect the cable from the wall.
Dave
A friend's house has been hit twice. He lost most of his electronic
equipment on the last occasion. His neighbour was worse off - his
meter box had to be replaced. Fortunately my friend was insured.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
R
Richard Freeman
Guest
"Bodgey" <ihate@spam.com> wrote in message
news:iSX5e.5584$5F3.169@news-server.bigpond.net.au...
In fact most Lightning damage comes from sources other than Lightning
strikes to MEN mains.
ie:
Phone Lines (yes even underground ones)
Aerials
and direct strikes to houses
news:iSX5e.5584$5F3.169@news-server.bigpond.net.au...
That is actually about as incorrect as you can get.
In fact most Lightning damage comes from sources other than Lightning
strikes to MEN mains.
ie:
Phone Lines (yes even underground ones)
Aerials
and direct strikes to houses
J
James
Guest
"Richard Freeman" <bogoff@nospam.spam> wrote in message news:<425cbbff_1@news.iprimus.com.au>...
Mains sure can bring in a lot of overvoltages - happens all the time.
True, the neutral is bonded to earth in many places (ie earth bar in
MSB, to every power pole, to high voltage earth etc). This isn't
saying stikes dont occur elsewhere but they often come in via the
mains. Its not only lighting either, tree branches can often force the
HV lines down onto the LV lines, sending 50Hz high voltage into
houses. While the lines will trip out on earth fault quickly it will
still cause damage to appliances.
Getting back to the OT, earthing the pole will help, but in the event
of a direct strike you'll still most likley do damage to your TV. What
it may do tho is prevent the many kA's coming inside and damaging lots
of other things too. Unplugging is best - I usually do that when
things aren't in use or a storm is approaching - lots of lightning
around here
Cheers
James
Mornin,
Mains sure can bring in a lot of overvoltages - happens all the time.
True, the neutral is bonded to earth in many places (ie earth bar in
MSB, to every power pole, to high voltage earth etc). This isn't
saying stikes dont occur elsewhere but they often come in via the
mains. Its not only lighting either, tree branches can often force the
HV lines down onto the LV lines, sending 50Hz high voltage into
houses. While the lines will trip out on earth fault quickly it will
still cause damage to appliances.
Getting back to the OT, earthing the pole will help, but in the event
of a direct strike you'll still most likley do damage to your TV. What
it may do tho is prevent the many kA's coming inside and damaging lots
of other things too. Unplugging is best - I usually do that when
things aren't in use or a storm is approaching - lots of lightning
around here
Cheers
James
R
Richard Freeman
Guest
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:42585A3F.74F10878@earthlink.net...
unpopular Earth stakes and exiting out via the Antenna...... After all the
Antenna is Metal remember ! (semi-quote from one of the more Technically
stupid movies I have ever had the Misfortune to watch - Hard rain )
The same
Lightning Strikes ....
it also damaged a computer and monitor that had no cables
news:42585A3F.74F10878@earthlink.net...
That is obviously the Lightning entering the MEN mains, avoiding all those
unpopular Earth stakes and exiting out via the Antenna...... After all the
Antenna is Metal remember ! (semi-quote from one of the more Technically
stupid movies I have ever had the Misfortune to watch - Hard rain )
The same
But where is w_tom ? he reckons that Telco equipment is never damaged by
Lightning Strikes ....
it also damaged a computer and monitor that had no cables
Just wait w_tom will be along shortly to tell you what really happened ;-)
F
Franc Zabkar
Guest
On Wed, 13 Apr 2005 16:28:03 +1000, "Richard Freeman"
<bogoff@nospam.spam> put finger to keyboard and composed:
on the mains would affect several households and would take out
expensive appliances. OTOH, a strike on the phone line may take out
your phone or your modem, but not much else. Strikes on aerials would
also be localised events.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
<bogoff@nospam.spam> put finger to keyboard and composed:
Hmmm, that seems counterintuitive. I would have thought that a strike
on the mains would affect several households and would take out
expensive appliances. OTOH, a strike on the phone line may take out
your phone or your modem, but not much else. Strikes on aerials would
also be localised events.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
B
Bazil
Guest
Franc Zabkar wrote:
look out. I saw two very dead and burnt motherboards that were connected
via modem to the phone lines. One was actually warped and twisted from
the heat. The strike was half a k up the road and just like Richard
mentioned, entered the phone lines through the ground. I don't know why
mains strikes seem to have a smaller radius of damage (maybe all the
neutral grounding? maybe the higher load presented by all the connected
appliances? higher capacitance? probably all of above), but it has
always been said to disconnect your modems during electrical storms.
Of course the reality is that a strike is going to cause damage to
whatever it hits. It's just where it goes and via what medium after that.
Bryan
Not at all. While that does happen, when lightning enters phone lines,
look out. I saw two very dead and burnt motherboards that were connected
via modem to the phone lines. One was actually warped and twisted from
the heat. The strike was half a k up the road and just like Richard
mentioned, entered the phone lines through the ground. I don't know why
mains strikes seem to have a smaller radius of damage (maybe all the
neutral grounding? maybe the higher load presented by all the connected
appliances? higher capacitance? probably all of above), but it has
always been said to disconnect your modems during electrical storms.
Of course the reality is that a strike is going to cause damage to
whatever it hits. It's just where it goes and via what medium after that.
Bryan
R
Richard Freeman
Guest
"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:9rkp5119m1u6l7epbe3q8gdfb97jnagiol@4ax.com...
communications and Computer installations following Lightning Strikes. my
observations where as follows:
Most damage to Computer systems was pretty well confined to equipment that
was connected to Data lines, Aerials and or internal building cabling (other
than AC mains) with equipment plugged into AC mains alone more often than
not surviving unscathed.
Arc tracks from Lightning consistently showed signs of arcing from unearthed
phone lines, aerials etc (line interfaces etc) typically across to chassis
and earthed equipment metalwork but I do not recall ever seeing evidence of
arcing from AC mains connections to Earthed metalwork.
cable itself - Conterary to popular belief underground cables are just as
susceptible to Lightning damage (some people I have spoken to have argued
that they are in fact more susceptible) as aerial cables due to effects such
as EPR,EMP etc In fact I have seen Lightning strikes that have blown over
200 surge arrestors off the MDF terminating an underground cable and still
destroyed equipment in the building and this from strikes to the cable over
100m from the building.
In fact one strike I cleaned up after at the most inappropriately named
Mount Peasant (google groups search for 'mt pleasant' in aus.electronics for
the tale - and other tales of my Lightning experiences) blew the tripe out
of 50 surge arrestors, damaged faxes, modems and Eftpos machines etc and
still damaged a connector at the other end of over 5kms of cable.
nature with the exception of Lightning strikes to phone cables.
It seems counter intuitive until you realise that MEN power Distribution as
the name suggests employs a Multiple earthed Neutral (a single earth stake
is in fact inadequate during a Lightning strike as a Lightning strike
usually causes an EPR often exceeding 100,000 Volts) is made up of
relatively low impedance cabling and often also employs lighting protection
such as earthed wires above the power lines etc.....
Regards
Richard Freeman
news:9rkp5119m1u6l7epbe3q8gdfb97jnagiol@4ax.com...
It is largely a Conclusion I drew having Visited/Repaired many Data
communications and Computer installations following Lightning Strikes. my
observations where as follows:
Most damage to Computer systems was pretty well confined to equipment that
was connected to Data lines, Aerials and or internal building cabling (other
than AC mains) with equipment plugged into AC mains alone more often than
not surviving unscathed.
Arc tracks from Lightning consistently showed signs of arcing from unearthed
phone lines, aerials etc (line interfaces etc) typically across to chassis
and earthed equipment metalwork but I do not recall ever seeing evidence of
arcing from AC mains connections to Earthed metalwork.
And every other Phone/modem/LI etc connected to that cable and often the
cable itself - Conterary to popular belief underground cables are just as
susceptible to Lightning damage (some people I have spoken to have argued
that they are in fact more susceptible) as aerial cables due to effects such
as EPR,EMP etc In fact I have seen Lightning strikes that have blown over
200 surge arrestors off the MDF terminating an underground cable and still
destroyed equipment in the building and this from strikes to the cable over
100m from the building.
In fact one strike I cleaned up after at the most inappropriately named
Mount Peasant (google groups search for 'mt pleasant' in aus.electronics for
the tale - and other tales of my Lightning experiences) blew the tripe out
of 50 surge arrestors, damaged faxes, modems and Eftpos machines etc and
still damaged a connector at the other end of over 5kms of cable.
That is correct In fact most Lightning damage I have seen is localised in
nature with the exception of Lightning strikes to phone cables.
It seems counter intuitive until you realise that MEN power Distribution as
the name suggests employs a Multiple earthed Neutral (a single earth stake
is in fact inadequate during a Lightning strike as a Lightning strike
usually causes an EPR often exceeding 100,000 Volts) is made up of
relatively low impedance cabling and often also employs lighting protection
such as earthed wires above the power lines etc.....
Regards
Richard Freeman