Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!munnari.oz.au!wcc!tom From: tom@wcc.oz (Tom Evans) Newsgroups: comp.dcom.lans Subject: Re: Req For Info - Ethernet Electrical Rules/Specs Message-ID: <410@wcc.oz> Date: 17 Oct 89 01:31:23 GMT References: <188.2526de30@acci.com> <580@trwind.UUCP> <850@maxim.erbe.se> Organization: Webster Computer, Melbourne, Australia Lines: 56 In article <850@maxim.erbe.se>, prc@erbe.se (Robert Claeson) writes: > In article <580@trwind.UUCP> johng@trwind.UUCP (John Greene) writes: > >In article <188.2526de30@acci.com> ta2@acci.com writes: > > >>2) Is is legal to run a pigtail of two or three feet from the > >> base of the BNC T to the Ethernet card? > > >This is a definite no-no. Not only would you be radiating all over the place > > I've actually seen this, and it worked. OK. What we ALL want (:-) is to have the cheapernet in the wall where it can't be broken, tripped over, left unconnected. What we want is a BNC on the wall, one on the back of the machine and a simple cable connecting the two. Too bad the electrical specs won't allow it This continuous bus-topology stuff doesn't make intuitive sense to people who's main connection with electricity is their home telephone, power and audio wiring :-). Now if thinwire could be made to LOOK this simple. **************** Now you CAN have this. For those who will be dreadfully offended by something that looks like an advert, junk this article NOW! **************** AMP Inc (Harrisburg PA) have a wiring system called "LAN-LINE Thinnet Tap System". It LOOKs like a simple cable from the wall to your machine. What it ACTUALLY is is a twin coax, running from the wall-plug, up to the BNC on the end of the cable and back to the wall-plug again. When you plug it into the special tap-assembly on the wall-plate, it trips a switch and your thinwire network just got 12' (or 16.4' or 24' ...) longer. Yes, it just did an insertion trick. Yes, it does break the network, but it's make-before-break and 500ms max., which is a lot faster than I can do it with BNC Tee pieces. It's also nicely insulated, so if your network administrator has left your local segment ungrounded (see grounding discussion, this group), and someone in the lab has dropped his end of the cable into the middle of an open PC power-supply, you won't be the one to find out by getting 110V (or 240V here) across you. How come no-one's mentioned the SAFETY aspect of Ethernet grounding? This stuff can transport mains power better than it does data. Disclaimer - All I have is a brochure from the local distributor - no other connection at all. --------- Tom Evans tom@wcc.oz | Webster Computer Corp P/L | "The concept of my 1270 Ferntree Gully Rd | existence is an Scoresby VIC 3179 Australia | approximation" Australia | 61-3-764-1100 FAX ...764-1179 | D. Conway