marka@dsinet (Mark Anacker) (11/03/90)
Hello,
We are about to order a bunch of coax for our ethernets around here, and
I am faced with a choice of two RG-58A/U cable types. One the one hand, we have
Belden 8259, which is the usual black PVC with a NVP of 66%. The other is
Belden 8219, which has a cellular polyethylene core and a NVP of 78%. Since
these are both 50 ohm cables, it looks like we would get more distance out
of the second type. My only fear is that this type of cable is too stiff to
handle easily.
Would anybody out there care to comment on their cabling experiences? I've
always used 8259, but if we can squeeze a little more performance out of out
cable plant, I'd switch. Thanks.oberman@rogue.llnl.gov (11/03/90)
In article <376@dsinet>, marka@dsinet (Mark Anacker) writes: > > We are about to order a bunch of coax for our ethernets around here, and > I am faced with a choice of two RG-58A/U cable types. One the one hand, we have > Belden 8259, which is the usual black PVC with a NVP of 66%. The other is > Belden 8219, which has a cellular polyethylene core and a NVP of 78%. Since > these are both 50 ohm cables, it looks like we would get more distance out > of the second type. My only fear is that this type of cable is too stiff to > handle easily. On thin Ethernet the Vp is not the citical factor. The limiting factor on cable length is attenuation. I'd look at these numbers (which I don't have handy). I'd also worry about stiffness as thinnet must be brought to the back of each system and may get flexed a lot. To stete the obvious, kinks in coax are NOT good! R. Kevin Oberman Lawrence Livermore National Laboratory Internet: oberman@icdc.llnl.gov (415) 422-6955 Disclaimer: Don't take this too seriously. I just like to improve my typing and probably don't really know anything useful about anything.
grr@cbmvax.commodore.com (George Robbins) (11/03/90)
In article <376@dsinet> marka@dsinet (Mark Anacker) writes: > Hello, > > We are about to order a bunch of coax for our ethernets around here, and > I am faced with a choice of two RG-58A/U cable types. One the one hand, we have > Belden 8259, which is the usual black PVC with a NVP of 66%. The other is > Belden 8219, which has a cellular polyethylene core and a NVP of 78%. Since > these are both 50 ohm cables, it looks like we would get more distance out > of the second type. My only fear is that this type of cable is too stiff to > handle easily. I'm a little fuzzy on the Belden numbers, but by all means go with the foam core stuff. It's actually a bit less stiff than solid polyethylene core. The cable I get also has an inner foil shield under the braid, which takes a few seconds extra to clip back. (don't make the mistake of not clipping it 8-( I may not matter, but if you check around you may be able to get other than the usual black, I've gotten grey from Cabletron, which is much less obstrusive if you do much running up and down walls or dangling from the ceiling. I don't know if it's a stock item, once I asked and they said the might be able to order it for me, once cables came in grey without asking... -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing: domain: grr@cbmvax.commodore.com Commodore, Engineering Department phone: 215-431-9349 (only by moonlite)
bruce@ccavax.camb.com (11/10/90)
> I am faced with a choice of two RG-58A/U cable types. One the one hand, we have > Belden 8259, which is the usual black PVC with a NVP of 66%. The other is > Belden 8219, which has a cellular polyethylene core and a NVP of 78%. Since Belden/DEC spent considerable effort to design a GOOD thinnet cable. There are many not so obvious things that got considered that have been documented enough times already. This cable (and other similar 'LAN-grade' cables) may not fit RG58 size BNCs. This isn't really a problem. Just order the BNCs that fit. The Belden numbers are: vinyl 9907 Teflon 89907 Belden has a new air-plenum grade cable insulation that crinkles less and is less expensive than Teflon, and I assume they are also making this cable using the new insulation, but don't know the number for it. DO get Belden, not the many other brands that are qualified to DEC's spec. Little problems (like getting the foil to strip easily...) can become major pains with cheaper wire. The actual price difference is tiny, so get the good stuff. Try 1.800.BELDEN4 (NOT 1.800.4BELDEN <the mistake I have made several times>).
phil@brahms.amd.com (Phil Ngai) (11/13/90)
In article <34770.273a9bb5@ccavax.camb.com> bruce@ccavax.camb.com writes: |DO get Belden, not the many other brands that are qualified to DEC's spec. |Little problems (like getting the foil to strip easily...) can become |major pains with cheaper wire. The actual price difference is tiny, so |get the good stuff. I want to second this. Belden is the best and the only cable you should use. The extra cost is tiny compared to the secondary costs of using inferior cable. Parts is parts but cable is not cable. -- KrystalNacht: why every Jew should own an assault rifle.
grr@cbmvax.commodore.com (George Robbins) (11/14/90)
In article <1990Nov12.180204.5239@amd.com> phil@brahms.amd.com (Phil Ngai) writes: > In article <34770.273a9bb5@ccavax.camb.com> bruce@ccavax.camb.com writes: > |DO get Belden, not the many other brands that are qualified to DEC's spec. > |Little problems (like getting the foil to strip easily...) can become > |major pains with cheaper wire. The actual price difference is tiny, so > |get the good stuff. > > I want to second this. Belden is the best and the only cable you should use. > The extra cost is tiny compared to the secondary costs of using inferior > cable. Parts is parts but cable is not cable. Let's get real here. Belden makes good cable, but there's nothing that magical about it to justify this kind of statement. On the other hand, I don't suggest you source your cable from Radio Shack or Joe's TV. We seem to usually end up with Times or Montrose - works good. -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing: domain: grr@cbmvax.commodore.com Commodore, Engineering Department phone: 215-431-9349 (only by moonlite)
oberman@rogue.llnl.gov (11/14/90)
In article <15840@cbmvax.commodore.com>, grr@cbmvax.commodore.com (George Robbins) writes: > Let's get real here. Belden makes good cable, but there's nothing that > magical about it to justify this kind of statement. On the other hand, > I don't suggest you source your cable from Radio Shack or Joe's TV. Now wait a minute! I've never tested Radio Shack RG-58, but their RG-59 and 300 ohm twin lead are among the best I've tested. Very good impedance control and loss that's well withing the spec. I've never had any problem stripping it, either. Radio Shack wire products are generally excellent. And I really don't like RS. Don't like any place that wants my address every time I buy a $2 commector. R. Kevin Oberman Lawrence Livermore National Laboratory Internet: oberman@icdc.llnl.gov (415) 422-6955 Disclaimer: Don't take this too seriously. I just like to improve my typing and probably don't really know anything useful about anything.