Martin Riddle said:
How about a poor mans TDR?
That would be good - in the mode of creature feep, a bnc connector would
be nice with the TDR as well (got a 250 footer that's gone bad
somewhere, but it's tie-wrapped to stuff here, in conduit there, and I
can't find it by inspection - though I'm probably just going to yank it
out as I already worked around it).
Mind you, I think the only "affordable" way to do TDR is if the poor man
already has an oscilloscope, and can drag it to the cable with a pulse
generator - but I'm willing to find out differently.
*** (not novel)
Cable ID (rabbit and ferret) - two boxes, one has signal injection and
the other can pick out the cable with that signal from the other N
unlabeled cables stuffed into some dank nasty part of a building. Signal
should not damage ethernet or phone devices if other end of cable is
plugged in.
*** (not novel)
End-to-end check - the second box can also plug into the far end and
make some sort of check on the cable with both ends far apart, as when
installed. Ideally this would be adaptive (ie, if one side of a pair is
broken, but some other wire goes through, the tester pairs up to find as
many good wires as possible, down to the logical lower limit of 2 wires)
*** (might be slightly novel, or I don't look at enough test equipment I
can't afford)
Once end-to-end check passes (at least for a couple of pairs), do some
end to end test patterns, ideally at various data rates, ideally
including rates exceeding the nominal operating rates for the sake of
peace of mind, or marginal link detection, or whatever you want to call
it.
ie, for Ethernet, run tests at 10BaseT speed, and 12 and 15 (not that
those exist) and 100 BaseT speed, and 120 and 150 (not that they exist),
and 1000 BaseT, and 1200 and 1500 (not that they exist)
....and we've probably passed right out of affordable, poor man territory
again.
***
For completeness, get a couple of surplus cell-phone vibrator things,
and switch those on at some point in the testing (in both boxes, perhaps
one at a time) to see if the connectors are flaky with motion.
