>What's wrong with RG-59? As far as I understand, the most important >thing is "impedance 75 Ohms", which RG-59 fulfills...
RG-59's impedance is fine, but it isn't what telcos traditionally use and it has other issues. Doing T3 cables at a customer site, or needing to do them fast in a strange city in the evening, go to RadioShack and even get the premade ones with F fittings and then get their F to BNC adapters. It will work well. Same goes for RG-6 which is much better for UHF than RG-59, but for T3 speed just shouldn't matter. If you have the high density BNC bulkheads on both the A nd B (left and right) side of the back of a cisco 15454 chassis (aka Cerent), you are facing 192 BNC connectors and with 4 of these fitting in a 7' rack, you simply don't want RG-59. RG-59 typical construction is PE and that burns way too well. You may be able to get a PVC jacket, but then it is toxic smoke. I'm sure there are plenum grades available, too, but it is a lower quality cable than 734 or 735, and it is way stiffer. It also comes in stranded or solid center and the F fitting folks rely on a solid center as that is their crappy center connector pin. Know what you are getting if you plan to use it. We normally stock it ONLY to use for use with the Symmetricom GPS dildo/antenna on the roof for CO master BITs clocks (takes a Trompeter TNC connector, same tooling...), and for any security cameras that are not IP. 735 is the small cable that is most commonly seen in bundles of "8-pack", or 9, 12, 16, or even 24. The center wire is 26 ga and is silver plated. A few years ago when several other cable providers were trying to capture more of Lucent's business, there was a lot of propaganda about the guage and percentage coverage of the braid which is already over foil. The supposedly important issue here was pull off strength for a BNC installed by joe q tech who may be a bit sloppy. If techs are equipped with good tools and good connectors (more on that in a minute) and have had even brief training, I think they will do very well with any of the available 735 cable. As the other brands tried to steal telco connector business from Trompeter, there were various telcos using the one-crimp connectors with the colored plastic rearends for 734 and 735. There were a couple of different styles from one vendor and the tooling and the connectors could not be interchanged. The tooling was even more expensive than the traditional all metal BNC two-crimp tooling, but these newer connectors were less expensive and claimed faster installation. I hated them, and think they were not as reliable, and have not been seeing them as much so I suspect others felt the same way. These one crimp ones predated the current waterproof with colorcoded ring one squeeze F and BNC connectors for RG-6 and RG-6 quad shield the cable guys now use, and I doubt these newest ones are made for 734 or 735. If you have any amount of connectors to do, you really need the "Trompeter" stripper that looks like a flashlight with a big head. These are actually made by the Eraser Co. in upstate NY. so shop for your best price. They come adjusted and with a sample stripped cable end. But learn the internal adjustments as they get fiddled with by differnet people and you may need to reset everything. The 734 cutter head in the standard 734 & 735 kit will strip RG59 in a pinch (with the correct strip length for Trompeter connectors if you have the correct one for your cable). The Trompeter ferrule crimp dies leave the die number embossed in the hex crimp. Their 12-point center pin crimper is really simple and just works well and isn't that much more than the 8-point one. If you buy these BNCs in large quantity direct, the price gets quite attractive. The Trompeter ones are well made here in the USA of quality materials. Single plastic bags that are scored to rip open are good for tool bags, but the 50 connector trays are best if you have a lot to do. It used to be that MilesTek had a supposedly imported BNC for 735 cable that was almost 1/2 what a Trompeter costs, but their prices have crept up and the Trompeter ones are very good. One dead T3 because of bad connectors, and you paid what you would have for premium connectors. OTOH, MilesTek is a huge Trompeter customer, so at least some of what they sell is the good domestic stuff, though I don't know what is imported vs OEM'd from Trompeter. One big problem with 735 is that it has about double the loss that 734 does (RG-59 is similar to 734 for loss) and all those LBO settings in feet to normalize signal levels at the DSX bays are assuming you have 734 cable. DOUBLE your actual 735 footage to get its 734 equivalent loss. Or to put it in practical terms, you can only go half as far on 735 cable. An additional plug for Trompeter is that after the mass confusion caused by there being NO standards for 75 ohm SMBs (which was standardized at 50 ohms) and every connector manufacturer doing a 75 ohm version differently and cisco having at least 2 DIFFERENT bastard versions (probably due to acquired company's earlier choices), Trompeter came out with a 75 ohm mini-BNC that is really nice and that some equipment vendors use and that "OF COURSE" crimps with the same standard Trompeter 734/735 tool kit. It is actually the strip length that is the biggest issue that they did do "right". Cutter heads are large, expensive, and having other strip length heads around would mean they WOULD be misapplied. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
