I've confirmed that I now have N connector intrusive taps! These have a N female connector on each end, like the leftmost transceiver in this picture:
https://oelzant.priv.at/~aoe/images/galleries/hardware/802_3_transceivers/DSC_0927_med.jpg I seem to recall the CCNA instructor telling us that you weren't really supposed to screw a 50 ohm terminator onto an intrusive tap; I don't know if there's good reason for it or if it was just a general practice. In any case, I've got 40 of the things now, which makes a lot of the existing transceiver surplus (usually missing the tap) useful again! Thanks, Jonathan On Tue, Jun 26, 2018 at 2:50 PM, systems_glitch <systems.gli...@gmail.com> wrote: > Indeed, the AMP coring tool is more a cutter than a drill, and it doesn't > go all the way to the center conductor, which would short out the segment > as the cutter is metallic. It doesn't screw in though, it has a shoulder > that stops on the seating surface of the vampire tap body. I don't know if > this is consistent with the original 3 mbit Ethernet, as I've never worked > with that. > > The "stinger" contact gets screwed into the threaded hole in the vampire > tap body. Some AMP literature refers to the stinger as being spring loaded, > but none of mine are, and I don't think any of the ones from CCNA days were > either. The shaft of the stinger contact is insulated, only the very tip is > bare. The tip is finished in a sharp conical point, which penetrates the > last little bit of the foamed dielectric and actually makes contact with > the center conductor. I don't know how far it penetrates into the copper, I > suspect it just displaces a small divot around itself. > > Cutting/coring is absolutely necessary to get through the quad shield > ground layer on real Belden 9880 or 89880 Ethernet coax. It's tough stuff. > I have to comb out the outer braid and cut the first foil layer to get the > inner braid to open enough for the N connector to seat! > > In case anyone was wondering about the color and designation, the yellow > coax is typically Belden 9880 and is non-plenum, whereas the orange stuff I > have is Belden 89880 plenum rated cable. > > If I had better video-recording equipment, I'd make a video of the N > connector crimping and tap installation process. I think it'd be easier to > demonstrate that way. > > Thanks, > Jonathan > > On Tue, Jun 26, 2018 at 2:37 PM, Noel Chiappa via cctalk < > cctalk@classiccmp.org> wrote: > >> > From: Paul Koning >> >> > I believe the original concept was just a probe that would poke >> through >> > the cable to contact the center connector. The drill came because >> the >> > cable was too tough to penetrate without it. >> >> No, the original 3 Mbit Ethernet also used a 'drill' (actually, a >> cylindrical >> cutter which screwed into the thread of the tap housing; threading which >> was >> then used to screw in the transceiver). >> >> Anyway, there has to be a hole cut _through_ the cylindrical ground layer >> (foil, or woven wire) around the center conductor. If you just stuck a >> probe >> into the cable to the center conductor, it would short it out. >> >> Noel >> > >