10base2 / 10baseT (again)

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Thu Nov 23 19:19:36 2000

OK, next question.

I've acquired a few Asante FriendlyNet Thin Adaptors. These are little
boxes about the size and shape of old Mac transceivers -- about 4" long, 2"
wide, 1 1/4" thick. One end has an RJ45; the other has a BNC sticking out
each side:

     ____________________ _
    | | { }
    | |_|_|_
    | |
    | _ _ _|
    | | | |
    |____________________| {_}

Inside is a standard 5V-9V DC-DC converter, a standard ethernet 3-section
transformer, and a perfectly ordinary DP8392 ethernet transceiver IC and
the usual discrete components (diode, a few resistors, etc) I associate
with an ethernet coax driver. So on the face of it, it looks like a
line-powered 10baseT to 10base2 converter. Oh yes, one other thing: the
BNCs are self-terminating; they have an extra contact set into the centre
insulation (with nothing plugged in, there's 50 ohms across core and
screen; with two plugs in, it's open-circuit).

But it doesn't seem to work -- so what is it really?
If it's any clue, they came from someone who's into Apple Macs.

-- 
Pete						Peter Turnbull
						Network Manager
						Dept. of Computer Science
						University of York
Received on Thu Nov 23 2000 - 19:19:36 GMT

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