View Single Post
  #28   Report Post  
Posted to alt.binaries.schematics.electronic,sci.electronics.design
FatBytestard FatBytestard is offline
external usenet poster
 
Posts: 86
Default Wiring a Wall Type RJ45 Jack

On Wed, 20 May 2009 21:22:01 -0700, 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.


You're an idiot.

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.


It isn't "at 1GHz" idiot.

The big push on
twisted pair is due to how much more easily it can be installed than
coax.


No, it isn't. It is for a more easily managed full duplex mode.

It makes far more sense to install twisted pair in a hub
arrangement than it does coax. It's far more economical.


Yes. It is also because that is all that is needed.

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.


Obviously.

Again, the only real advantage is a skinnier cable and the
ability to hot-plug the units.


You're an idiot. Optics are serial too, yet they can reach speeds that
are beyond the comprehension of a twit like you... apparently.

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.


You're an idiot. The interface is far faster than the read speed of the
drive. Serial attachment is fine.

Then again, I wont
be making the kind of money Intel will by cornering the market with
unnecessary SATA technology.


Your retarded opinions are what is unnecessary.

We should remember what happened to IBM
and OS2 when they tried to foist a technology on a public that did not
want it.


What? The Power PC CPU is one of the most successful on the market.
They never "tried to foist" a goddamned thing on us, you dumb****ing
retard.

Where do you get your bull**** statistics from?