i can see hear that people have compared copper wired utp (unshielded twisted pair) cable (Cat5e for example) that are used for computer networks that has 4 pairs, if using full duplex mode on network then 2 are used for each way of transmition with the current being turned on and off, with the emf created by the pairs havin to directions it created a sort of shield around the cable, as it has to put up with 240v for ur household power. and in high quality rca cable used in car audio are made of a lot high quality products the signals that they transmit are of a constant current of varying voltages, and each wire carry similar but not always the same voltage, for this reason i believe that they are twisited but rca's also have a shielding round them that protect from noise, thats why in have noise areas of computer networks they use STP (shielded twisited pair). but its costs are **** loads more than UTP so thats why it is not used more often.

these are just my thought, so if i am wrong and there is most likey a high degree that i am please feel free to correct me.

ben

i've done a little physics, but it's pretty sketchy now..

the strength of an emf is directly proportional to the CURRENT carried, not the voltage. the strength also decreases inversely proportionally to distance, ie for every equal distance you move away, the power of the emf is reduced by 1/2

from my point of view, buying 'shielded' rca's is pointless. emf's are extemely difficult to eliminate, and no material can physically block the field, without the field being attracted to it (in the case of rca's, the shielding is on the cable conducting the audio signal, hence the emf is induced into the shielding AND the signal cable)

for further detail read:
http://www.magnetic-shield.com/faq/faq.html

i'm sure a lot of people will like to disagree, but it's a very controverisal topic (it's like saying mobile phones cause cancer [although it has been found that there is no direct link, and the cause is either non-existant or indirect])

anyway, i shall leave you to ponder

alex

Anyone else got any thoughts

There is an article that takes that link above to absolute pieces, 1 step at a time. It's been posted here before.

I'll have a look, see if I can find it.

quote from the link

"Computer networks use TRUE BALANCED LINE systems, that means that the two cables that carry each signal are exactly the same, same length, same construction, same thickness, same impedance, same capacitance! But so are the senders and receivers of the signal in the wire... So not just the two conductors in the wire are the same but the amplifier that sends the signal out has the same characteristics in both of its terminals, and the receiver at the other end of this wire also has identical characteristics in both of the terminals... Each of the two equal wires also carry an equal signal (although electrically inverted) when in use, there is actually an amplifier for EACH of the pair and a receiver for each wire in the pair"

no ethernet 802.3 standard via cat 5 is not differnetial unless you use the t4 standard which use all the conductors in the cat 5 cable...hmmmmm havent seen this in networks that ive worked on. If ya have noise porblems we use optical now.

Normal ethernet 802.3 uses 2 pair one pair for tx one pair for rx. Thats 4 conductors. Differnetial requires at least 6 (tx 3 cables 2 signal 1 common ground).

Also cat5 is designed with differnet twistings on each pair to reduce cross-talk so the inductance and capacitance of each pair is different.

RS422 is a balanced line transmission standard this is a serial communication standard like the normal non differential rs232 serial port on the back of all our pcs.

howerver it is interesting to see that the standard rcas induced less noise when they were close to the neon light.

with that being said coax has always been better for noise rejection in data communication. Cat5 has taken over due to ease of installment, cost and better dsp noise elimination techneques.

it would be good to do some tests similar to eddies to see what happens.

pitty eddie does not have his facts right about the typical ethernet network we use everyday.