external data cable

[tony sayer]

In article , dennis@home scribeth thus

If your going 5.b Ghz make sure it does the 5.7 to 5.8 part of the band and conform to the Ofcom IR 2008 regs..

[dennis]

802.11a is OK in the UK, its doesn't need a license unless it interferes with an essential service. It won't as it such low power but they wanted to cover themselves when they allowed its use.

[Andy Wade]

By "valve IC" do you mean a multiple valve with resistors and capacitors integrated in the envelope? That idea originated in Germany in 1926 - see

[w_tom]

Do what BT does. Every building interconnects to theirs - the same problem repeated 10,000+ times.. BT must never have damage because every wire (inside every cable) gets connected to earth. Having no damage was routine even 100 years ago. Protection is not provided by surge protectors. Protection is about earthing every wire to the same earth ground. Either a wire connects directly to earth OR a surge protector makes that earthing connection.

View these protectors:

has what provides protection - a green ground wire. What makes the protector effective? That ground wire must be as short as possible to earth. Earth is where surge energy gets dissipated harmlessly.

When a wire interconnects two buildings, then one building can act like a lightning rod; second building act as an earth ground. Then anything connected to that wire gets damage. As Andrew Gabriel noted, communication ports have significant internal protection rated at 2000 or 15,000 volts. This protection exists in ethernet ports, in telephone equipment, etc. So why are these devices harmed? That protection can be overwhelmed by the typically destructive surge. If every wire entering or leaving a building connects (ie less than 3 meters) to earth ground, then that protection inside electronics will not be overwhelmed - as BT demonstrates in every town.

Single point earth ground. That ethernet wire is earthed (via a protector) to the same ground used by AC electric - and that earthing wire must be short. Then surges out of one building will not destroy electronics inside the other.

BT has been doing this protection for how long? Effetive protection from direct lightning strikes has been routine for how long? Why do so many not know this (the reason for so many confusing answers)?

[Bob Eager]

(his usual lengthy stuff)

See, I told Simon that he'd stir up w_tom again...

[Dave Plowman (News)]

Must be something wrong with my telephone - and every other one I've seen. No local earth. Nor would you expect one with a balanced line.

Oh - if you earth every wire it will cease to be of any use...

[David Hansen]

On Mon, 19 May 2008 23:05:40 -0700 (PDT) someone who may be w_tom wrote this:-

You may think they have no damage, but in reality they do have damage which is why they employ people to fix things.

Open wires on pole routes suffer rather more damage than conductors in cables. That is why the Post Office and their predecessors employed people to fix things.

[w_tom]

First, you are in the UK where BT only installs earthing on their end. In North America, every phone line is earthed at both ends.

BT's switching computer is challenged by maybe 100 surges during every thunderstorm - and no damage. New master socket installations do not have that earthing - that is even required by code in North America.

Second, balanced line remains because - well read the previous post with care. Every wire in every phone line cable gets earthed through a protector - therefore remains a balance line. What does a protector do? Performs like an open switch. Only connects a wire to earth when a surge exists.

Surge protectors don't stop or block surges. See the examples at:

effective protector makes that short (ie less than 3 meter) connection to earth - that green wire. Each ethernet wire gets connected to earth ground only during surges. Then that surge need not find earth ground, destructively, via any switch or network card. Then that surge will not overwhelm thousands of volts protection in every ethernet interface.

Third, does BT shutdown service for five days while they replace that =A3multi-million switching computer? Of course not. Hundreds of surges during every thunderstorm and no switching computer must be damaged. A protector is only as effective as its earth ground. Earth ground provides ethernet protection.

Another industry professional demonstrates this solution in an application note:

is to connect communication wires between buildings and have no damage. Those who would deny this also claim surge damage is acceptable. Nonsense.

[Dave Plowman (News)]

So they don't use balanced lines?

Obviously different ways of skinning a cat.

Right. So they're not actually earthed, then? You should have made that clear. What happens in a fault condition is something else.

Do we actually speak the same language?

[Bob Eager]

See, I said you'd stir him up again!

[dennis]

I bloody well hope not, I didn't do my job very well if it did. Even if it did there were some switches built into containers that could be installed. They were used following a few disasters like fires.

[tony sayer]

I reckon you ought to come over here and see what plant BT actually have and how they go about all this earthing;!...

I don't think they are that much bothered these days;(..

[tony sayer]

In article , w_tom scribeth thus

Course a lot of comms stuff in the UK is on fibre now, doesn't seem that bothered by Jove's bolts;)...

And a lot of BT copper disappears in the night with the Pikey's spiriting it away;!..

[Rod]

If any of them read uk.d-i-y, they'll be after HiFi speaker cables...

[w_tom]

Therefore all those switches were damaged when fiber did not exist? Of course, not. It is routine to interconnect buildings with wires and not have damage. There is zero reason to solve this problem with fiber. A solution is so simple as to be standard even long before the transistor existed.

Many have confused the OP with recommendations and futility that did not exist and was not necessary even 70 years ago. It is routine and simple to have surges without damage. Defined was effective protection for ethernet cables. But as the many professionals note, earthing must exist for all incoming wires. Every incoming utility must connect to earth ground directly or via a surge protector.

[w_tom]

How earthing is accomplished was plainly stated and easily read in that first post:

How could you not understand that? Amazing how one knows, but never bothers to learn or read the science.

Also bluntly stated was that telephone lines are balanced lines while each wire makes a connection to earth ground. Why is that so difficult? If you still don't know what a protector does - if you are still listening to popular myths that promote ineffective protectors - then how earthed phone lines (via protectors) remain balanced would confuse you. Those myths can only survive if you ignore details =96 such as ignoring what was in the first post.

Posted were concepts that have been standard protection without damage for over 100 years. A superior solution that also costs less money. A protector is only as effective as its earth ground, so that (thousands of volts) protection inside routers and NICs is not overwhelmed. That single point earth ground provides protection. Provided were examples of effective protectors to make that connection from each ethernet wire to earth =96 to do what BT also does in every telco switching station.

[tony sayer]

So how do you a fibre cable then?..

[David Hansen]

On Wed, 21 May 2008 00:28:53 -0700 (PDT) someone who may be w_tom wrote this:-

Mind reading is also one of your "talents"? Fascinating.

[funkmish]

I've seen it done with 2.4Ghz wi-fi directional antennas at each end of an empty duct underground. Worked fine and the ground shielded it from interference...

[w_tom]

Squirrels, manufacturing defects, downed wires, customer changes, rain, vibration, etc mean that people are employed for the rare and infrequent failures. Near zero failures times how many subscribers means a busy and tiny repair staff.. No protection is perfect. What happens when surges do damage? What did Orange County FL finally do when direct lightning strikes caused damage to the emergency communication equipment? They employed people to fix things. They fixed the reason for that surge damage. They - corrected defective earth ground:

Yes, due to age, earth ground must be repaired to terminate surge damage. Why? Damage from direct lightning strikes is unacceptable. When that rare failure occurs, employees eliminate that failure AND defect that permitted it to occur. Earthing is why hundreds of surges during every thunderstorm can never cause damage in any telephone switching station. Earthing is how an ethernet cable is routed between buildings to eliminate router and NIC damage - a solution that makes the fiber optic solution rediculous, expensive, wasteful, and unnecessary. A protector without earthing provides ineffective ethernet protection.