Talk:10BASE5

RG

• RG is not short for Radio Grade but Radio Guide IIRC

and for the connectors UG = Union Guide

• asin waveguide

Linuxlad

• How do you know? maybe the RG stands for Really Good.

• • Not likely. But if you want to find out, you could just look up RG (but the article isn't consistent...) Not that it really matters, it's not RG-anything, and certainly isn't at all like "RG-8X". Paul Koning 01:11, 14 April 2007 (UTC)

Vampire tap wasn't the only (or original?) way to go

When I first started working with "garden hose" in the mid-1980s, transceivers had screw-thread coaxial fittings, meaning that in order to insert one into an existing run, one had to cut the cable (network down, sorry!), install connectors on both ends of the cut, and attach the transceiver (network back up! ...assuming you did it right the first time).

I don't know (or this would be in the article :-), but my impression is that vampire taps were a later innovation to simplify this process immensely. The transceiver in the picture looks awfully familiar, and I wouldn't be surprised if it isn't the same model of transceiver we eventually adopted; from Cabletron, if memory serves.--NapoliRoma (talk) 05:18, 21 December 2007 (UTC)

I haven't seen the sort of transceiver you mentioned. Who made those? As for "original" vs. "later innovation", probably not. Digital, for one, shipped vampire tap transceivers from the start, and I don't believe we ever considered the approach you described. So perhaps it was a simpler approach used by some other manufacturers, who didn't want to bother to figure out how to make vampire taps work? Paul Koning (talk) 12:04, 21 December 2007 (UTC)

Who made those?

3Com, I'm pretty sure, which puts it essentially right at the origin of Ethernet itself.

Digital was kind of late to the game with Ethernet, weren't they? (And jeezly expensive at first. I remember being quoted a 5-digit figure to get Ethernet/TCP for our PDP-11 RSTS systems—can $50K/system be right?—so they stayed in their own separate DECnet environment for years after everything else was on TCP/IP.) So it's entirely plausible that you had the good fortune to be able to go straight to vampire taps.--NapoliRoma (talk) 15:11, 21 December 2007 (UTC)

I couldn't find a photo anywhere, but here's a drawing...--NapoliRoma (talk) 15:48, 21 December 2007 (UTC)

Well, "DIX" means "Digital, Intel, Xerox". DEC was one of the three companies that created Ethernet. Sure it was relatively expensive; the original DEC Ethernet controller was the DEUNA, which took two "hex size" Unibus controller boards. So at the usual price of $2k per board that ended up a $4000 device. But remember, that was before single chip NICs existed. The first DEC controller that used an approximation of a single chip NIC was the much-cursed DEQNA. It was much smaller, and also so poorly designed that it was finally scrapped after 14 revisions.

It may be that 3Com actually produced the first commercial NIC, before DEC. I don't remember the precise timeline that far back anymore... Having 3Com be first wouldn't be too surprising; after all DEC was a notoriously slow company while 3Com was a hungry startup. Then again, the DEC product worked, and the 3Com 3c501 didn't. (It worked only so long as your application was really really slow -- it had a single packet buffer.)

As for TCP for RSTS, that never was a DEC product. I forgot who sold that. $50k seems outlandish but who knows. Certainly both hardware and software were much more expensive in the minicomputer era than in the PC era.

Paul Koning (talk) 16:31, 21 December 2007 (UTC)

That's what I love about WP: you can learn something new every day... I've managed to go a couple of decades working with Ethernet without ever running across the "DIX" acronym. Apologies for undercrediting DEC here. But yeah, this didn't seem to trickle into their products very quickly, at least not the older ones. I remember I could telnet into our first VAX from day one, though, which was a happy thing.

The first Ethernet NICs I worked with were actually Multibus cards for Sun-2s, which would have been either 3com or Sun's own, according to the WP page; we probably even originally got the transceivers through Sun. But yeah, we eventually wound up buying 3C501s and 3C503s like popcorn once PCs started making their inevitable incursion. (You might be interested to know that after a careful evaluation we originally standardized on DEC Rainbows rather than IBM PCs; seemed like a good idea at the time...)

But I did have a point to all this other than stirring up old brain cells better left in dormancy. In the article, it currently reads

10BASE5 cable is designed to allow transceivers to be added while existing connections are live. This is achieved using a vampire tap

I think this is overstating the case. I don't think the cable or spec was originally designed for piercing taps, but that this was a very clever idea that came later. However, my only evidence at this point is my personal experience (saw and used N connector transceivers first), and some deductive reasoning (why wouldn't you use vampire taps if they were available?). In short, WP:OR at this point. But I think the article should be modified to read something like

Transceivers can be added to 10BASE5 cable via N connectors or with a vampire tap; the latter makes it possible to add transceivers without interrupting existing connections

--NapoliRoma (talk) 17:36, 21 December 2007 (UTC)

Vampire taps are older than ethernet. The 3 megabit ethernet for the Xerox Alto used cable TV cable and taps. I believe that they are still used for cable TV, though not the exact same ones. 10base5 transceivers are made with either vampire taps or N connectors. Early 10base2 used transceivers with N connectors and N to BNC adaptors. Gah4 (talk) 06:06, 14 January 2017 (UTC)

When was it used?

The year of introduction and years of (relative) popularity would be useful here.. '''Jason404''' (talk) 03:46, 21 September 2008 (UTC)

Spacing

The question of spacing the Vampire Taps on yellow hose comes up regularly on Usenet. It has nothing to do with the "wavelength" of the signal. According to the guy who did the design work and wrote the specification (whose name I forget - this is not my field, I just spotted the subject, perhaps you're reading this?) the whole thing was based on a statistical simulation which led to development of a simple rule-of-thumb for installation engineers. The idea was to avoid crowding too many taps together, which would have created a big reflection by constructive interference. The precise spacing and positions are unimportant, but became something of an urban myth, resulting in cupboards full of coiled up surplus cable...

Regards, everyone, Derek Potter —Preceding unsigned comment added by 83.105.15.249 (talk) 09:49, 6 March 2009 (UTC)

Well, it has slightly to do with wavelength. You don't want many taps close to multiples of the wavelength, as the reflections will add. So, the chosen spacing is such that taps won't be on multiples of the wavelength, and won't cluster too close to each other. As I understand it, there was thought to making the spacing random, but it was difficult to build a machine to apply randomly spaced marks on the cable. The chosen spacing is such that any combination of 100 taps on a cable will avoid reflection problems. Gah4 (talk) 06:16, 14 January 2017 (UTC)

Baseband v broadband v passband

From reading the articles on Baseband and Broadband, I would have thought that "baseband signalling as opposed to broadband" is incorrect.

Seems to me that baseband in this case is referring to the fact that its frequency range starts at zero, not that is of a limited range, and that it should "be considered as synonym to lowpass, and antonym to passband, bandpass or radio frequency (RF) signal."

The Broadband article lists "Baseband" as an antonym only in the case of video.

I'm not an expert so I don't know what the best term to use is, but I suspect it should be "baseband signalling as opposed to passband"? CupawnTae (talk) 21:11, 30 March 2010 (UTC)

Broadband is a funny term, but the primary use is in terms of TV signals with 6MHz bandwidth. There is 10broad36, a form of ethernet designed to coexist with TV signals on a cable, and predecessor to today's cable modems. Broadband means that the bandwidth is not small relative to the carrier frequency. More complicated filters are needed than for narrowband. Gah4 (talk) 06:25, 14 January 2017 (UTC)

Obsolete

10Base5 was superceded by 10Base-T years before wireless networking became popular. The main drawback of 10Base5 wasn't low transmission speed, they are all 10Mbps, it was the huge pain thicknet was to install and maintain. 71.202.81.207 (talk) 22:41, 3 June 2011 (UTC)

Despite the installation difficulties, 10BASE5 did have a major benefit over the much easier to install 10BASE2 in that unlike 10BASE2, users couldn't disconnect a cable or terminator from a BNC T connector behind their computer and take down the entire network (or subnet). This is one of the reasons 10BASE2 was so quickly displaced by 10BASE-T in commercial environments when 10BASE-T compatible hardware became readily available. --Tothwolf (talk) 17:06, 4 June 2011 (UTC)

Photo problem

I believe that the included photo Image:Xerox PARC ethernet cable.jpg is not a 10Base5 cable but a 3 megabit /sec Ethernet cable. 10Base5 is the standard version. 3 megabit/sec Ethernet preceded that. Ethernet != 10Base5 Remaker (talk) 19:12, 20 December 2011 (UTC)

Was there some difference between the 3Mbps hardware and the 10Mbps hardware? The equipment in the photo looks exactly like the 10Mbps equipment I worked with in the mid-1980s.--NapoliRoma (talk) 05:42, 23 December 2011 (UTC)

FWIW, I found a closeup photo of the transceivers in that exhibit: they're labeled "BICC Isolan type 1113". I can't find a specific reference to that model, but the fact that they're that formally branded leads me to believe they're specimens from later than the (brief) 3 megabit era.--NapoliRoma (talk) 21:55, 1 January 2012 (UTC)

All of the equipment in the photos is 10Base5. The middle photo is my gear so I know it is 10Mbps. The top and bottom photos use the universal style transceiver tap shoe which was introduced in the mid to late 80's well after the transition from 3Mbps to 10mbps. Robert.Harker (talk) 00:12, 2 September 2016 (UTC)

The Xerox 3Mb/s ethernet uses 75 ohm TV cable and cable TV taps. The transceivers don't say anything on the outside. The 10base5 cable and taps were specifically designed for ethernet. Gah4 (talk) 06:29, 14 January 2017 (UTC)

Disadvantages

The logical simplicity of tapping new nodes onto the in-place network cable is complicated by the on-site craftsmanship required to successfully install a tap, and the dire consequences of a mishap during installation. It isn't all that hard. I did it for some years, with the cable in a cable tray above my head, and never had a problem. I started with a brand new, and so nice and sharp, tap tool. If you use an old, dull, tool you might have more problems. Worst case, you cut the table and put N connectors on it. Gah4 (talk) 06:32, 14 January 2017 (UTC)

I've edited and taken that uncited material down a notch or two. ~Kvng (talk) 14:32, 16 January 2017 (UTC)

I don't believe a reference should be required to make summary conclusions about the logistics that follow from the specifications: one mishap ruined the whole works. References would be a matter of testimony to what was experienced but never documented. Your experience was happy, but many others were not. Of course it's only of historical interest now, but documenting the design flaws of something obsolete will educate about not repeating this sort of bad design principle in the future. --Richard J Kinch (talk) 15:15, 25 January 2017 (UTC)

Wikilinks to Fast Ethernet and Gigabit Ethernet on 10BASE5

(moved from User Talk:Zac67) Hi there, just trying to understand about the deliberate "deeplinking" on 10BASE5. What's the purpose of it? It's not that big a deal either _way, just puzzled why someone would intentionally want to wikilink to a redirect in this case. Waggie (talk) 02:44, 16 February 2020 (UTC)

@Waggie: The text refers to 100BASE-TX which is a section in Fast Ethernet the redirect 100BASE-TX directly jumps to, which Fast Ethernet by itself doesn't. The redirect has another purpose when 100BASE-TX might be split into a seperate article. --Zac67 (talk) 09:15, 16 February 2020 (UTC)

can you buy it?

Belden, the one that seems to have made it, has "request quote". This one seems to sell it for $7216.40 for 1000 feet. Gah4 (talk) 11:24, 8 April 2023 (UTC)