I am about to run an eight wire cable to link two computers together. The distance is about 70 feet. In measuring the resistance between the ends of the wire before installing, the VOM reads the resistance at 7-8 ohms on each of the wires. Is this too much, or good enough? Wm.

A serial connection like we spoke of on the Win3.1 forum? I've done it with a 100' serial cable and with a CAT3 cable w/ adapters...had no problems. Skip

I'm not so familiar with resistances, but I do know Ethernet UTP wire is good for up to about 100m. At least that's what CCNA1 has taught me :) My opinion, you probably won't see any performance issues or lost packets. If you're really that worried, you can get some more wire and throw a hub inbetween to split the distance in half. The hub should repeat the signal, but add a hair of latency to the link. Just my thoughts...wouldn't put too much weight on em.

Wm, Dug out a 100' 28awg serial cable and resistance measured about 21 ohms. You'll be fine...sounds like you're using about 24awg wire. Skip

The DC resistance has little to do with whether a network cable will work or not. The REAL issue is whether the line will pick up interferance from other sources, and whether it is of good "quality" so that it doesn't distort the data pulses so much that they won't trigger at the other end. That is why we have the oldest, poorest phone line, the old tan 4 conductor, that won't support very high data rates for very far. Next up is "cat 3" which at least has SOME twist and some order of balance. Higher quality is "cat 5" which has a tighter twist, and better quality control in manufacturing. Those of you old enough to remember television twin lead, CAT5 works sorta the same way, that is-- it is a balanced "feedline" and as long as it remains balanced, and doesn't suffer from too much "loss" plus when twisted that helps the line to cancel noise pickup from outside sources. It doesn't carry DC current, and the actual resistance is not that big a problem, long as the end connectors are properly made.

Skip: Wire gauge is 26. Ex-Pacific Telephone wrapped wire. Measured the resistance before soldering up everything, just to make sure no breaks in wire that was not evident. Got the 7-8 Ohms then. Soldered them onto the new 9 pin connectors, and as of this morning the reistance shot up. I now suspect the poor connection to be due to poor connectors. Wm.

G'day The determining issue here is not so much the resistance of the cable at DC. The impedance of the cable is what is important: that is a combination of the resistance of the cable and its capacitance; This forms a low pass filter which will alter the signal. The frequency of this filter will determine the attenuation of the signal. Over short distances, this will not affect most systems because the filter break frequency will be much higher than the fundamental frequency of the signal: it does;however ,come into play when you increase the distance. As has already been noted, telephone lines suffer from this and data links using RS232 type signals have strict limits on the length of, and type of, cable to use. regards, Elric