battan@qtc.UUCP (Jim Battan) (08/02/89)
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. My questions: Can ThinWire cable coexist on same or different segments with RG58A/U? What coax stripper is used with ThinWire cable? Xcelite technical support says they don't make a compatible stripper. Can I use the same AMP or Amphenol connectors that are now in use on our RG58/U cable? If not, what are the correct part numbers? Can I use the same crimper (a Paladin hex crimper for RG58)? 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.) Thanks for any help you can offer. Please post follow-ups; I'm sure others would be interested in the discussion. -- Jim Battan uunet!sequent!qtc!battan +1 503 626 3081 Quantitative Technology Corportation (QTC) 8700 SW Creekside Place, Suite D Beaverton, OR 97005
pat@hprnd.HP.COM (Pat Thaler) (08/12/89)
> 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