> On Aug 26, 2016, at 10:24 AM, Joseph Zatarski <jzat...@illinois.edu> wrote:
>
> ...
> Yes, the whole reflection thing could get into a bit of a complex
> discussion involving transmission line theory, but I am an electrical
> engineer, so here goes:
>
> Yes, you need proper termination at either end, or else you get the wrong
> voltages on the line and cause 'collisions' (well, detect collisions
> anyway, though there aren't really any until the first reflection comes
> back from the cable end).
That reminds me of an amusing error in a 1980s trade rag for DEC users ("The
DEC Professional"). It discussed how you could mix 10Base5 and 10Base2 hosts
by coupling the two size coax cables through an N to BNC adapter. That's fine
so long as you use the 10Base2 limits. But instead of a barrel adapter, the
article had a photo showing a T connector at the transition, with a
"terminator" attached to it. So that network had three terminators: one at
each end and one in the middle. I suspect it didn't work, or at least quite
poorly.
paul
