Lightning and modems

Several years ago, my built-in dial-up modem was evidently damaged by
static electricity from a nearby lighting discharge. Anyhow - it no longer
worked and I had to get an external modem. Since then I always unplugged
the phone line from the modem during stormy times or when the computer is
not in use. Normally I don't use the computer if thunder is in the area.

Now I have DSL. Should I unplug the phone line from the CenturyLink C1000A
modem as I did with the other or is it protected? Anyone know? Or found out
the hard way?

TIA


--
You know it's time to clean the refrigerator
when something closes the door from the inside.

KenK wrote:
Several years ago, my built-in dial-up modem was evidently damaged by
static electricity from a nearby lighting discharge. Anyhow - it no longer
worked and I had to get an external modem. Since then I always unplugged
the phone line from the modem during stormy times or when the computer is
not in use. Normally I don't use the computer if thunder is in the area.

Now I have DSL. Should I unplug the phone line from the CenturyLink C1000A
modem as I did with the other or is it protected? Anyone know? Or found out
the hard way?

TIA



I would treat it the same as your other modem.

I've looked at pictures of ADSL PCBs, and I
don't "see any magic" on there. It's just as
exposed as a dialup modem.

Paul

On 29 Sep 2014 17:28:53 GMT, KenK wrote:

Several years ago, my built-in dial-up modem was evidently damaged by
static electricity from a nearby lighting discharge. Anyhow - it no longer
worked and I had to get an external modem. Since then I always unplugged
the phone line from the modem during stormy times or when the computer is
not in use. Normally I don't use the computer if thunder is in the area.


Not using the computer is meaningless. You should unplug it, not just
refrain from using it.


Now I have DSL. Should I unplug the phone line from the CenturyLink C1000A
modem as I did with the other or is it protected?


The risk is exactly the same. Unplug it.


Anyone know? Or found out
the hard way?


Do *not* rely on using surge protectors. Most of them are little more
than fancy extension cords, and offer next to no real protection.

KenK wrote:
Several years ago, my built-in dial-up modem was evidently damaged by
static electricity from a nearby lighting discharge. Anyhow - it no longer
worked and I had to get an external modem. Since then I always unplugged
the phone line from the modem during stormy times or when the computer is
not in use. Normally I don't use the computer if thunder is in the area.

Now I have DSL. Should I unplug the phone line from the CenturyLink C1000A
modem as I did with the other or is it protected? Anyone know? Or found out
the hard way?

TIA

ADSL uses the same 2 wires that your pots line did.
So does VDSL.
Keep unplugging your phone line in storms.
That's what I do.

On 29 Sep 2014 17:28:53 GMT, KenK wrote:

Several years ago, my built-in dial-up modem was evidently damaged by
static electricity from a nearby lighting discharge. Anyhow - it no longer
worked and I had to get an external modem. Since then I always unplugged
the phone line from the modem during stormy times or when the computer is
not in use. Normally I don't use the computer if thunder is in the area.

Now I have DSL. Should I unplug the phone line from the CenturyLink C1000A
modem as I did with the other or is it protected? Anyone know? Or found out
the hard way?

TIA

Basic surge protection offers only limited help regarding static and EM from lightning stikes.
I've lost one dial-up modem to a nearby lightning stike and had one ADSL router corrupted (luckily I
was able to reset and reconfigure after much effort).

You have to ask yourself if you really want to take the risk and how much /money/time/effort you
want to spend fixing the damage after a lightning stike? Personally, I would prefer to avoid the
hassle and simply play it safe. Your choice.

On Mon, 29 Sep 2014 17:39:54 -0700, wrote:

....snip...

If you buy decent surge protectors and assure your grounding is good,
there is no reason to ever unplug anything.
I am in the lightning capital of the world and I have not lost
anything in 30 years.

where is 'lightning capital'?

"RobertMacy" ha scritto nel messaggio
newsp.xmz525gq2cx0wh@ajm...

where is 'lightning capital'?

Florida?

wrote:
On Mon, 29 Sep 2014 11:38:24 -0700, "Ken Blake, MVP"
wrote:

On 29 Sep 2014 17:28:53 GMT, KenK wrote:

Several years ago, my built-in dial-up modem was evidently damaged by
static electricity from a nearby lighting discharge. Anyhow - it no longer
worked and I had to get an external modem. Since then I always unplugged
the phone line from the modem during stormy times or when the computer is
not in use. Normally I don't use the computer if thunder is in the area.

Not using the computer is meaningless. You should unplug it, not just
refrain from using it.


Now I have DSL. Should I unplug the phone line from the CenturyLink C1000A
modem as I did with the other or is it protected?

The risk is exactly the same. Unplug it.


Anyone know? Or found out
the hard way?

Do *not* rely on using surge protectors. Most of them are little more
than fancy extension cords, and offer next to no real protection.

If you buy decent surge protectors and assure your grounding is good,
there is no reason to ever unplug anything.
I am in the lightning capital of the world and I have not lost
anything in 30 years.

I think it's still healthy to ask the question, of whether
certain types of surge protectors affect ADSL. That isn't answered
here, but at least someone asked the question.

https://community.bt.com/t5/ADSL-Cop...ed/td-p/375299

The original phone network, only has to pass 4KHz, and so impairments
to the line are allowed to be different, than they would be if attempting
to pass a megahertz baseband signal (2.2MHz on ADSL2+).

In the pictures he

http://www.kitz.co.uk/adsl/btsockets.htm

the BT main plate uses something I don't recognize.

http://www.kitz.co.uk/adsl/images/phone/components.png

Is that a gas tube ? It looks too thick for a MOV.

One difference between their phone system and ours,
is their ringer signal is carried on a third wire. Whereas
our ringer is HV AC carried on the line pair.

*******

If your modem is capable of reporting line statistics,
you can compare performance (noise margin) with and without the surge
protector in place, and see if it makes any difference.

I worked with an engineer, who was tasked with putting
surge suppression on an Ethernet interface (higher frequencies
than ADSL), and his comment at the time was that it
was pretty difficult to find a protection device that
didn't degrade return loss. He was experimenting with a
semiconductor device, which has two devices in series
inside, the first device with a very low junction capacitance,
the second device more robust. And the combination was
intended to keep capacitance down to the picofarad level.
But the device probably doesn't have all that high a surge
rating. I didn't look at all the details at the time,
but at least noted there was yet another flavor of
protection available.

*******

So I plugged return loss into the search engine, and found this
article.

http://www.epanorama.net/newepa/2012...nd-protection/

And rather than worry about the details, all I can say is
you'd want to do a noise margin test with and without the
surge protector in place, to see if the surge protector
might be the wrong type.

Paul

On Mon, 29 Sep 2014 20:39:54 -0400, wrote:


Do *not* rely on using surge protectors. Most of them are little more
than fancy extension cords, and offer next to no real protection.

If you buy decent surge protectors and assure your grounding is good,
there is no reason to ever unplug anything.


I completely disagree. First, note that a decent surge protector is
expensive, the better part of $100. Those that are around $15-25 are
useless junk.

Second, even the best surge protector can do nothing more than
substantially reduce the risk. It can not eliminate it. The only way
to eliminate risk entirely is to unplug.

And by the way, the best kind of surge protector is a whole house
surge protector, not any of those that go between the computer and the
electrical outlet.


I am in the lightning capital of the world and I have not lost
anything in 30 years.


That's like saying. "For the last 30 years I have worn a seat belt
when driving my car, and I haven't been killed yet."

Consider yourself lucky.

On Tue, 30 Sep 2014 08:10:13 -0700, Paul wrote:

...snip....some really good info just to keep Aioe happy

And rather than worry about the details, all I can say is
you'd want to do a noise margin test with and without the
surge protector in place, to see if the surge protector
might be the wrong type.

Paul

I've designed systems that pass beyond 1GHz, and keep out 50kV trash. Just
have to make the protection system a 'design' [I could find nothing nearly
as good off the shelf.]

The aforementioned design only had to protect the electronics. Another
such protection design REQUIRED passing the 1MHz+ data WHILE being zapped
AND still meet full product's communication specs! That design was more
challenge.

On Tue, 30 Sep 2014 11:10:13 -0400, Paul wrote:

One difference between their phone system and ours,
is their ringer signal is carried on a third wire. Whereas
our ringer is HV AC carried on the line pair.

It is in the BT system. There are only two wires from the exchange, an
RC network in the master socket spits out the ring signal to the ring
wire. Thus the third (ring) wire is only present in the premises and
even that is not needed with modern equipment since they extract the
signal internally. With ADSL in the UK it's often recommended to
disconnect the ring wire at the master socket to get less noise.

--
Faster, cheaper, quieter than HS2
and built in 5 years;
UKUltraspeed http://www.500kmh.com/

On Tue, 30 Sep 2014 08:36:42 -0700, wrote:

...snip...

Central and south Florida
We have a thunderstorm every day in the summertime and some will have
flash bang strikes several times (the time between flash and bang is
virtually imperceptible)
I had the lightning rod on my weather station hit several times. Once
I lost a serial card in the PC that runs it. After fixing the surge
protection on that line, the worst that happened is I needed to reboot
the PC.
...snip...to keep Aioe happy

I was going to guess Florida!

I was there inone of your summer storms and remember many flash/bangs!

All your constructions sounds good! I agree about 'should be able to keep
operating' attitude. just a matter of understanding the principles and
designing for them.

On Tue, 30 Sep 2014 14:52:11 -0400, wrote:

On Tue, 30 Sep 2014 08:16:18 -0700, "Ken Blake, MVP"
wrote:

On Mon, 29 Sep 2014 20:39:54 -0400, wrote:


Do *not* rely on using surge protectors. Most of them are little more
than fancy extension cords, and offer next to no real protection.

If you buy decent surge protectors and assure your grounding is good,
there is no reason to ever unplug anything.


I completely disagree. First, note that a decent surge protector is
expensive, the better part of $100. Those that are around $15-25 are
useless junk.

Somewhat true


Second, even the best surge protector can do nothing more than
substantially reduce the risk. It can not eliminate it. The only way
to eliminate risk entirely is to unplug.


If you never took it out of the box it would last forever. Are you
going to rush home from work to unplug everything?


No. First of all, I'm retired these days, so I don't have to rush home
from work. Second, when I was working, and even now, when I'm not, if
I was leaving the house for any length of time, if thunderstorms were
forecast, I would unplug before leaving. And regardless of forecasts,
if I were leaving for multiple days, I would unplug before leaving.


And by the way, the best kind of surge protector is a whole house
surge protector, not any of those that go between the computer and the
electrical outlet.

That is just the first line of defense, not the whole solution


That's fine. I don't disagree with that point of view.

"Ken Blake, MVP" wrote in message
...

On Tue, 30 Sep 2014 14:52:11 -0400, wrote:

On Tue, 30 Sep 2014 08:16:18 -0700, "Ken Blake, MVP"
wrote:

On Mon, 29 Sep 2014 20:39:54 -0400, wrote:


Do *not* rely on using surge protectors. Most of them are little more
than fancy extension cords, and offer next to no real protection.

If you buy decent surge protectors and assure your grounding is good,
there is no reason to ever unplug anything.


I completely disagree. First, note that a decent surge protector is
expensive, the better part of $100. Those that are around $15-25 are
useless junk.

Somewhat true


Second, even the best surge protector can do nothing more than
substantially reduce the risk. It can not eliminate it. The only way
to eliminate risk entirely is to unplug.


If you never took it out of the box it would last forever. Are you
going to rush home from work to unplug everything?


No. First of all, I'm retired these days, so I don't have to rush home
from work. Second, when I was working, and even now, when I'm not, if
I was leaving the house for any length of time, if thunderstorms were
forecast, I would unplug before leaving. And regardless of forecasts,
if I were leaving for multiple days, I would unplug before leaving.


And by the way, the best kind of surge protector is a whole house
surge protector, not any of those that go between the computer and the
electrical outlet.

That is just the first line of defense, not the whole solution


That's fine. I don't disagree with that point of view.

When I leave for a long period of time, I not only unplug the power cord to
the computer, I also unplug the Cat cable from my computer, just in case.
Is it necessary even though I have an APC Battery Backup with built in
suppressors, I don't know, but I feel better that way.
--
Buffalo

On Thu, 2 Oct 2014 11:41:30 -0600, "Buffalo"
wrote:

"Ken Blake, MVP" wrote in message
...

On Tue, 30 Sep 2014 14:52:11 -0400, wrote:

On Tue, 30 Sep 2014 08:16:18 -0700, "Ken Blake, MVP"
wrote:

On Mon, 29 Sep 2014 20:39:54 -0400, wrote:


Do *not* rely on using surge protectors. Most of them are little more
than fancy extension cords, and offer next to no real protection.

If you buy decent surge protectors and assure your grounding is good,
there is no reason to ever unplug anything.


I completely disagree. First, note that a decent surge protector is
expensive, the better part of $100. Those that are around $15-25 are
useless junk.

Somewhat true


Second, even the best surge protector can do nothing more than
substantially reduce the risk. It can not eliminate it. The only way
to eliminate risk entirely is to unplug.


If you never took it out of the box it would last forever. Are you
going to rush home from work to unplug everything?


No. First of all, I'm retired these days, so I don't have to rush home
from work. Second, when I was working, and even now, when I'm not, if
I was leaving the house for any length of time, if thunderstorms were
forecast, I would unplug before leaving. And regardless of forecasts,
if I were leaving for multiple days, I would unplug before leaving.


And by the way, the best kind of surge protector is a whole house
surge protector, not any of those that go between the computer and the
electrical outlet.

That is just the first line of defense, not the whole solution


That's fine. I don't disagree with that point of view.

When I leave for a long period of time, I not only unplug the power cord to
the computer, I also unplug the Cat cable from my computer, just in case.
Is it necessary even though I have an APC Battery Backup with built in
suppressors, I don't know, but I feel better that way.


Necessary? Perhaps not. Safer? Definitely!