OT: Direct Bury LAN cable

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I agree -- under normal circumstances -- that is is fine. However, if the wires get nicked and wet underground, it is a bit more of a potential problem.

But more important, in my mind, is the same reason that I dislike having modems plugged in when there is a thunderstorm around. Either the phone line or the power line may get hit by lightning. At that point, one line gets yanked up to thousands of volts, and the other is still near ground -- causing damage to whatever is between them -- usually the computer and modem. (In my case, the CSU/DSU for the 56k frame relay is what goes out with a near lightning strike. I lose one to a lightning strike about every other year. So far, the maker has fixed it and returned it free. (However, we had new phone cables put in the ground along our block about a year and a half ago, and so far (fingers crossed) we have not (yet) been hit.

I keep a couple of spare CSU/DSUs around (actually, three at the present) for quick return to service. But they came from hamfests and eBay auctions, not from the maker at the normal price. And *so far* -- the next thing down the line -- the Cisco router -- has not been damaged. I now have a spare for that, too.

Answering machines are another example of a very vulnerable device.

Home computers, with a modem *inside* the box, increases the chances that the rest of the system will be taken out when the modem is. I always go for an external modem.

Enjoy, DoN.

Reply to
DoN. Nichols
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And always leave a nylon string in the pipe - so you can pull a new cable and a new string through when needed.

It is very hard to push wire that far. Pulling is hard, but easier when there is a string...


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Actually, a direct lightening shot to the sales barn is what started all this trouble. Fried two computers and the RG59 cable between them. And started a static problem with the phone line that got a lot worse this fall.

I spent the day running a "Mexican Backhoe". Man, does my back ache this morning. Plus a big blister on my digging foot. It will take at least one more day to finish the dig. Not today, my body needs to recuperate.

I found that Menards sells direct bury telephone wire for 30 cents a foot, cut off what you need. For that price, I'm laying in a separate phone line even if most folks say its not necessary.


P.S. Thanks for the CAT 5 wire, Glenn

Reply to
Karl Townsend

If he's too stupid to follow instructions, and crosses pairs, he'll have problems. Cat 5 is 4 pair, twisted. The twisted pairs are for common mode noise rejection. What is induced in one wire of the pair is cancelled 100% by what is induced in the other wire of the pair, so at the end only a very tiny noise signal, if any, is seen. Then, to add more to the mix, each pair is twisted with the other 3, so that if a PAIR has a heavy current flow, each of the other 3 pairs acts in the same manner to reduce THAT noise to next to nil.

Now, split (or cross) pairs, and even ethernet traffic alone can , and will, produce lost packets due to crosstalk. Ethernet is a packet passing protocol, which DOES produce collisions, even on a 100% clean line - so even if the odd collision/lost packet were to result, it is 100% transparrent in operation.

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If you haven't wired these connectors before, note that the orange pair goes to pins 1 and 2. The green pair goes to 3 and *6* of the RJ45.

Blue goes to 4 and 5, and brown goes to 7 and 8 (unless you break them out to a separate RJ11 phone connector).

If you try to wire a CAT5 cable straight through, with each pair of wires going to adjacent pairs of terminals on the RJ45, as would seem to be logical, it won't work properly at 100 mb, though it may still work at 10 mb.

I haven't researched it, but I've been told that the odd ordering of the green pair is an artifact of backwards compatibility with an older wiring standard.


Reply to
Gary Coffman

One of the differences in weather between Minnesota and Florida is the height of the troposphere (the layer of the atmosphere in which weather happens). I learned this recently from my father, an old WWII fighter pilot. I had never heard of it, so looked it up. The troposphere is about twice as high at the equator as at the poles.

This is one reason besides average temp that southern thunderstorms reach such towering heights compared to northern latitudes, and may be responsible at least in part for the much higher incidence of lightning in Texas and Florida compared to Michigan or Minnesota.

Just thought I'd pass that along since this seems to be the general repository of odd knowledge.

Pete Keillor

Reply to
Peter T. Keillor III

What Jim said.

My son has three computers in different rooms in his home. When he started internet access with the cable company. He wanted to put them all on the broadband with Internet Connection Sharing.

All his phones were wired with CAT-5 wire so asked me if we could put a home network on the unused pairs and change out the outlet plates on the modular telephone phone boxes to combination network and phone boxes. I told him I didn't think it would work but he wanted to try it so we wired it up. The single CAT-5 comes into each box, one pair feeds the phone jack, two pairs feed the network jack. I put a cheap ($40?) router in the basement, plugged the broadband and network into that and away it went.

This is a little ugly because each RJ-45 jack plugged into the router has about three feet of the blue pair hanging out and going to the telephone demarc.

But it works perfect and has never missed a lick. I even started continuous pings (to an address outside the house) on all computers and called in and let the phone ring and it didn't even change the ping rate that I could tell.

Reply to
Jack Erbes

Pneumatic mole. It is a smaller diameter air hammer with a pointed end. They will drag the feeding air line a long ways. You have to be careful with them, if the tunnel collapses behind the mole you have to dig it out.

Reply to
Jack Erbes

Even more embarrassing if you aren't paying attention when backing it out and back over the air line and kill it half way across the taxiway! Gerry :-)} London, Canada

Reply to
Gerald Miller

There is another style which pumps lots of water through the thing to dig out in front of it, and there is some degree of steerability on the thing.

The brand which I saw in use where I used to work was called a "FlowMole". (Or was that "FloMole"?)

Good Luck, DoN.

Reply to
DoN. Nichols

sorta like losing a drill bit in a deep well? --Loren

Reply to
Loren Coe

Im using a beldon cable, 6 pairs---runs 10 base t and 3 telco lines as well as a 70.7v audio distribution at 10 watts.

The cable is listed for overhead service as well as direct burial.

The line is appx 500 ft.

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