Thicknet/10base5 Test Segment: The Cable is In!

[systems_glitch]

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.glitch at 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 at 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
>>
>
>