OK folks - It looks as if no one here seems to know WHY the spec is 330 ft. It has to do NOT with signal degredatiuon so much as with the timing used in the collision avoidance for ethernet. The further the run, the longer signal takes to get from point A to point B. That means there can be to long a gap between the time of the start of transmission and the time the signal is heard on the other end. If the other end tries to transmit during the gap, since it doesn't hear anyhting on the wire... bang! both packets interfere with each other and get trashed. You have a collision. You can go WAY over 330 ft in many cases, but if you are not using a switch, you will get a LOT of collisions. That is of course a moot point if you are using a switch - I've seen 700ft runs off switches that had NO problems at all when I slapped a sniffer on and looked for errors. Depends on the signal strength the devices (on BOTH ends) put out and the quality of the cable - the lower the attenuation the longer ya can go.

Then again, I have also seen 100mbs ethernet run over a 50ft cable run of silver satin (ie: flat, non twisted pair cable) with not ALL that many errors. :-)