In message , "Dave Plowman (News)"
writes
In article ,
Andy Champ wrote:
On 29/03/2013 23:58, bm wrote:
+1 In 48 years I've never needed one. If I can't fix it with a
DMM/AVO, scope, logic analyser etc it either 'aint worth fixing or I'm
incapable. Maybe it depends on the type of kit you're playing with.
Same as TDRs, never needed to use one.

I've never had a TDR, but several times wished I did. It would have been
really nice in the days of thinnet to be able to press a button and get
an idea of which plonker had undone the t-piece, and if that wasn't
enough to binary chop until I had him.

Luckily I've never been full time networks

Wot's a TDR?

http://en.wikipedia.org/wiki/Time-domain_reflectometer


Invaluable for finding cable faults in large buildings and beyond.

I keep a simple one
http://www.norbain.co.uk/downloads/d...structions.PDF
for checking CCTV cabling and have used others on 100V line PA, I had
500m+ of cabling at an Open Golf course a few years ago that had gone
short and being in a hurry grabbed the nearest BT engineer and persuaded
him to lend me his TDR for a couple of minutes, it took me to within
feet of the cable. The inaccuracy was probably down to my pacing out of
the distance!

When my neighbours electric supply failed a few years ago the leccy
board opened up a joint in the pavement and TDR'd the underground cable
to his house and found the break within a foot of where they thought it
was, a brick used as infill 50 years before had finally damaged the
cable.

So all in all a very useful bit of kit.
--
Bill