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- Path: sparky!uunet!mcsun!uknet!edcastle!hwcs!adrian
- From: adrian@cs.hw.ac.uk (Adrian Hurt)
- Newsgroups: sci.electronics
- Subject: Re: Coax Question
- Message-ID: <1992Jul27.125000.9458@cs.hw.ac.uk>
- Date: 27 Jul 92 12:50:00 GMT
- References: <1992Jul20.140143.19341@yang.earlham.edu> <1992Jul22.052519.901@athena.cs.uga.edu>
- Sender: news@cs.hw.ac.uk (News Administrator)
- Organization: Dept of Computer Science, Heriot-Watt University, Scotland
- Lines: 38
-
- In article <1992Jul22.052519.901@athena.cs.uga.edu> mcovingt@athena.cs.uga.edu (Michael A. Covington) writes:
- >In article <1992Jul20.140143.19341@yang.earlham.edu> jeremiah@yang.earlham.edu (Jeremiah Wilton) writes:
- >>I am wondering what kind of coax is used in Ethernet thin and thick wire
- >>connections. I am unconvinced that some really expensive special stuff
- >>is necessary. Might not RG-58 or 59 work for thinwire? How about
- >>composite video cable (the thin cheap stuff)?
- >
- >Thinwire Ethernet is RG-58 (52-ohm).
-
- According to my catalogues, there are:
- Uniradio M43: 50 ohms, one solid 0.9mm central conductor, braid screen.
- RG-58C/U: 50 ohms, 19x0.18mm stranded central conductor, braid screen;
- RG-58B/U: 50 ohms, one solid 0.8mm central conductor, braid screen;
- Thin Ethernet: 50 ohms, 19x0.2mm stranded central conductor, braid and
- foil screen (foil round the insulator, braid round the foil);
-
- The above list is in order of price, cheapest first. All of them work in
- a thin-wire Ethernet network; our network, to be exact. We took no chances
- and used the real, official, genuine thin-wire cable for most of it, but
- we have a mixture of the types for leads connecting wall sockets to machines
- on desks. It does not seem to have caused any problems, and we have some
- quite long segments. We also have a neat device called a Cable Scanner,
- which sends a pulse down the line and analyses what comes back, and can
- also display the results on an oscilloscope; it is basically a cheap time
- domain reflectometer. And I can't see any reflections caused by these
- different cables. Connectors are another matter, though. Another
- department used some sort of insulation displacement connectors called
- "Thinnet taps", and they show up nicely. Stick to BNC connectors.
- Preferably crimp connectors. Not only is it easier to install a crimp
- connector than a solder conector, but the crimp types provide better
- screening than the solder types I've seen.
-
-
- --
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