Wiring a Wall Type RJ45 Jack

Jeez, dude, just go look up the friggin cat5e spec... and shutup.

The Internet is pretty goddamned handy.

[snip]

I'll second the recommendations for surge protection. Also watch out for voltage differences between building grounds. I did such a run for GenRad Portable Products Division (nee Omnicomp) in the mid '80's, and observed about 15VAC between the two building "grounds" :-(

Ended up devising my own transformer drive/receive scheme.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 Stormy on the East Coast today... due to Bush\'s failed policies.

Here is a LCOM link that would help on lighting protection.

Cheers

Lighting protection?

Surge devices are not for "Lightning Protection" as a lightning stroke would indeed make it all the way into your product if it hit.

Surge protection devices are just that. Protection from surges, and only then, up to a certain point.

OK show me a lighting arrestor for Cat6(5e).

That is what I said. I said that there is NO SUCH THING.

Do you have reading issues?

No reading issues here, it's just that you never stated that there is 'NO SUCH THING'.

Cheers

What part of "surge devices are not for lightning protection" do you not understand?

So, yes, you DO have reading problems,because your response treated my post as if I was stating that lightning does get 'arrested' by such devices. I never made any such statement. Jeez...learn to read.

No you didn't. All you said is that "Surge protection devices" are not "for Lightning Protection" but you did not address whether there is some other device suitable "for Lightning Protection"

Inside your house? No, there isn't. If your house is struck, it can cause damage to any device inside the home, depending on where it strikes and how big it is.

I have seen it hit a barn's lightning rod and produce three nice ball lightning phenomena at about 9 inches in diameter each. I have seen it hit a roof of a two story and make a man standing on the back porch pull a spasm leap several feet, and he was drunk.

That one killed our 1962 Zenith floor model that lasted all the way until 73. So even tube type circuits are susceptible.

Those voltages can get wherever they want. It made it all the way down here from all the way up there. There isn't anything down here that you can use to isolate it, unless you have huge plastics casting facilities that can do a mold a couple hundred feet tall.

All we do in the home is suppress surges.

On Wed, 20 May 2009 21:22:01 -0700, snipped-for-privacy@how.com wrote:

: :>Actually, not at all. Swapping green and orange swap whole pairs, not :>swap wires within each pair. : :They get tighter as you move up, away from the blue/white pair. On a :25 pair CAT 5 arrangement, the last pair, voilet/grey, is twisted so :tight it's hard to unravel. At the frequency most establishments run :at, the impedance difference between the O/W and G/W doesn't add up to :a hill of beans. : :I'm not into the arguments used in favour of twisted pair cable. The :only reason they are getting away with twisted pair at 100 Mhz is :through liberal use of bs. For one, the signals are digital and even a :barely legible digital signal can be picked out of background noise :with a Schmidt trigger. Try connecting a high-frequency analog signal :through twisted pair and see how far you get. : :Another matter is the claimed throughput as opposed to the actual :throughput. Most telecom signals are regulated to 30 Mhz to prevent :broadcasting of signals to adjacent equipment. That means the 100 MHZ :claimed for CAT 5 regular is never used at that frequency. It could :be, theoretically, but it never is because signals are multiplexed to :get that throughput while running at a much slower frequency. A good :example of that is the DSL signals sent down a normal telephone :twisted pair which is rated at about 10 Mhz on a good day. DSL is :accomplished with quadrature modulation, which piggy-backs signals on :top of each other. : :Talking about 1 Ghz twisted pair is a serious joke. They get that by :using all 4 pairs on the cable, plus multiplexing. There's simply no :way that twisted pair will ever catch up with coaxial cable and you :simply cannot use a twisted pair line at 1 Ghz. The big push on :twisted pair is due to how much more easily it can be installed than :coax. It makes far more sense to install twisted pair in a hub :arrangement than it does coax. It's far more economical. : :Now we're seeing a push towards SATA over PATA. Although a hard drive :is a serial device, and a PATA signal has to be serialized to write to :the hard drive, I don't see what's being accomplished by converting to :SATA. Again, the only real advantage is a skinnier cable and the :ability to hot-plug the units. : :It just makes no sense to push data transfer one bit at a time when :you can do it 32 or 64 bits at a time in parallel. Then again, I wont :be making the kind of money Intel will by cornering the market with :unnecessary SATA technology. We should remember what happened to IBM :and OS2 when they tried to foist a technology on a public that did not :want it. :

AIUI, the lan cabling base rates are UTP (or STP) ethernet 10BaseT, 100BaseT or

1000BaseT. This means that the "data transfer rate" is either 10Mb/s, 100mb/s or 1000Mb/s.

There is no MHz transmission bandwidth involvement at all.

Simplicity itself. 1000 baseT to fiber. Run fiber between buildings, then fiber to 1000 baseT. Hurts the wallet. Works. Don't use fiber that has conductors bundled with it. In the case of a direct strike, you are always screwed, but not putting conductors out there where they can cause pickup helps, and the fiber link would at least keep the damage to whichever building got struck. Of course, if you are connecting power between the buildings, that can serve as a method for lightning pickup.

For people with budgets, surge suppressors are more practical, but far less bombproof. I use:

In the case of a direct strike, I expect them to be vaporized. But a direct strike is not all that common.

--
Cats, coffee, chocolate...vices to live by

See also: PCI-E. Supposedly, at insane data rates (real circuit bandwidth >

1GHz), even if signal quality can be managed, propagation skew between bus lines is ever more difficult (have you seen all the squiggles on a motherboard between processor, northbridge and RAM?). So why not skip bus width altogether, crank the clock rate (pushing circuit bandwidth even more though), and use multiple asynchronous channels. The advantage lies in clocking each stream at its own rate, rather than clocking 32 or 64 bits at an identical rate. Bytes could arrive out-of-order, but buffering done on-chip is a lot faster than a maze of wires on-board.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

This guy actually knows what is going on. Fiber IS the ultimate "creepage distance".

This 'reflects' proper avenues as clock rates climb (a little data transfer joke there). Definitely the right way. Managing little capture buffers is far better than managing errant data. I'll bet that serial allows one to downsize error correction overhead as well... or could/should anyway.

Never say never.

According to your "wherever they want" theory one would never even bother building transmitting towers or power distribution systems because mother nature is just going to destroy it with the next thunderstorm yet, while nothing is indestructible, we find it possible to achieve acceptable reliability.

Which, if done properly (the magic non trivial word), is generally sufficient because direct strikes to the home structure, especially in urban areas, is relatively rare as the power distribution system acts as a lightning rod and primary ground path so, in the vast majority of cases, 'surges' are what you're dealing with in home "lightning protection."

It's simply bad logic to suggest that since the 1 out of a million case can destroy just about anything that there's no point in protecting from the other 99.9999% of cases.

Never say never.

According to your "wherever they want" theory one would never even bother building transmitting towers or power distribution systems because mother nature is just going to destroy it with the next thunderstorm yet, while nothing is indestructible, we find it possible to achieve acceptable reliability.

Which, if done properly (the magic non trivial word), is generally sufficient because direct strikes to the home structure, especially in urban areas, is relatively rare as the power distribution system acts as a lightning rod and primary ground path so, in the vast majority of cases, 'surges' are what you're dealing with in home "lightning protection."

It's simply bad logic to suggest that since the 1 out of a million case can destroy just about anything that there's no point in protecting from the other 99.9999% of cases.

I get boggled between MB's and Mb's so I tend to think in Mhz or Ghz. To me, a bit is a transition from 0 V to max +ve (maybe 5V or 15V) then back to 0. IMHO, the only time to worry is when a constant stream of 1's and 0's is being sent. Then the voltage is being switched on and off regularly with a 0 between 1's. That to me is a full cycle which can be expressed as 1 hz, with the negative cycle missing.

I realize it's not technically correct but we're not concerned with the number of bits as much as we're concerned about the bandwidth, frequency-wise. In other words, what would be the difference between a

100 Mhz analog square wave transmission and a 100 Mb/s transmission of alternating 1's and 0's?

With respect to what you said about the data transfer rate, you have to be a lot more careful. Data is not necessarily 1's and 0's, it could be ASCII throughput which is measured in bytes per second. Data has to be meaningful and you have to specify whether it's being sent on a carrier. In fact, the modulation protocol determines a lot about the transmission, and that's why the MMC code, etc., was developed.

Schemes like that get higher throughput by manipulating the data. When several 1's appear in a sequence, or several 0's, they have a way of transmitting that information at a lower throughput.

When they measure CAT 5 throughput, they are talking bandwidth, which is the number of 'bits' you can transfer in 1 second. There is no such thing in CAT5 or 6 technology as a 1 Gb/s throughput on a single pair. It is simply not possible. I was questioning their claims for an actual 100 Mb/s throughput since that kind of frequency is generally not seen in practice. I'm sure it has been done in the lab and that it can be reproduced, but at 100 Mh/z you have a lot more to worry about in a big system such as overall radiation from the wiring system.

Like I said, many systems are regulated by governments that limit them to a throughput of 30 Mhz. Even if CAT 5 can pass 100 Mhz on a single pair in a lab, where is that ever used in practice? DSL is being passed on cable with bandwidths that can't exceed 10 Mhz. How is that done? It's done with modulation tricks that pass more information on a lower bandwidth line.

I smell Hallerts. Is that you you dumb-f*ck Pommy bastard? You knew nothing about audio last time I swore at you and now you're trying to talk telecom. Fuck off!!

I'm not interested in your pathetic opinions or your ad homs. Any d*****ad can call someone an idiot, trying to appear as if he has a clue what he's on about. Obviously your just a troll who knows nothing about basic telecom.

You can't even tell the difference between a Ghz and Gb/s and that's because you don't understand basic eectronics. That's what kind of technically challenged dumbass you are. Go back to school clown.

Oh, my...the troll knows big words. Full-duplex and half duplex have got nothing to do with what I'm talking about. If you were using coax, you'd use a data highway with taps on it. You can't run twisted pair like that because it has a length limit of 100 metres, including the patch cables. So you run it as a hub because the individual lengths are unlikely to exceed 100 metres in a hub.

Have you ever asked yourself why twisted pair has such a limit? Do you understand waveguide theory, or what capacitance and inductance does to twisted pair at high frequency? Do you understand skin effect? The only skin you're likely to know anything about is what might be left on the end of your dick.

You understanding of telecom is about zilch. I'm used to fat, f*ck trolls like you who have no life and nothing better to do than comment on blogs and newsgroups.

Holy shit. I've seen some dumb trolls but you're in the running to take the cake. 'Optics??'. You're talking about the transmission of light down a glass rod. What has that to do with twisted pairs of copper? Are you really that stupid?

Charges travelling through copper have to contend with the impedance of the conductor pairs.That impedance increases dramaticaly with frequency and is limiting well below 1 Ghz. Also, at higher frequencies, the charges start to use the skin layer of the copper. Coax is designed for that and it can handle 1 Ghz with ease.

Why you would compare either of those to photons of light travelling down a glass rod beats me. Can you seriously not understand why light travels faster in a serial mode than electrical charges in a copper medium? What a dumbass.

That was my point f*ck face. You need to buffer them anyway, but the processor needs to do more work than being involved in data transfers. It leaves much of it up to the DMA controller but the faster you can transfer data the better all around. There is no advantage of using SATA over PATA, other than smaller cables and hot-plugging, so why change technology in mid-stream? If you weren't so stupid, you'd be able to see that it's make people a lot of money.

It's been a long time since I kicked a troll's ass. Thanks for being my bum boy.