Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!ucbvax!hplabs!hpda!hpcupt1!hprnd!pat From: pat@hprnd.HP.COM (Pat Thaler) Newsgroups: comp.dcom.lans Subject: Re: 10BASE2 cable help wanted Message-ID: <2230021@hprnd.HP.COM> Date: 11 Aug 89 23:01:34 GMT References: <442@qtc.UUCP> Organization: HP Roseville Networks Division Lines: 31 > Jim Battan writes: > I'm in the process of converting our thin coax Ethernet from a mixture of > RG58/U and RG58A/U to something that is within the IEEE spec and > electrically consistent. I've heard numerous conflicting opinions about > what to do, from this newsgroup, computer manufacturers, and coax cable > makers. I know I want one of RG58A/U, RG58C/U, or IEEE 802.3 10BASE2 > (aka ThinWire) cable. I'll be using UTP when we move to our new building > in eight months (if the 10BASET spec is approved by then), but need some > new coax now. This is for a network of 35 Suns, a Sequent, several DEC > VAXen, and a GatorBox, all talking through a DEMPR and DELNI. > > Are the technical advantages of fully IEEE-compliant cable (e.g. Belden > 9907) worth the extra cost (cable, new connectors, new crimper)? > (We're not up against any of the 10BASE2 limits (#nodes, length) yet.) > > Jim Battan uunet!sequent!qtc!battan +1 503 626 3081 > Quantitative Technology Corportation (QTC) > 8700 SW Creekside Place, Suite D Beaverton, OR 97005 > ---------- When we wrote the 10BASE2 standard, we targeted the media specifications on RG58A/U and RG58C/U. I believe that cables which comply with the mil specs for RG58A/U and RG58C/U will also comply with the 10BASE2 specifications. (I have seen products labelled as RG58A/U or C/U which did not apear to comply with the mil spec behind the label.) It has been a while since I worked on coax, but my recollection is that the difference between RG58A/U and C/U is that one has a foam dielectric. The foam dielectric is more subject to impedance discontinuities if the cable is crushed. Pat Thaler