I go to lots of facilities where other engineers have run in fibre and the story is often the same – broadcast engineer who knows a bit about fibre and knows a firm who’ll pre-make him tight buffered cable. Now – aside from the fact that tight-buffered cable for installation is never optimal why do they always choose the cheapest patch-cord cable rather than robust cable?
Anyhow – after a chat with an instructor at Tyco recently I realised you can light up a fibre with a visible laser and the light will spill out at a bad splice. How often have I puzzled over which end of a loose-tube cable has the bad splice? The tester tells you you’re losing 5dBs of optical power but without a Fluke DTX-1800 (or other fibre OTDR tester to hand) you can never tell which splice is to blame.
The picture shows a bad splice (but not that bad – it was only loosing 5.5dBs – so would be fine on 2gig and probably fine on 4gig, but not optimal). The little red dot in the middle of the splice protector was a lot clearer than this ‘phone-photo shows.
The Maplin keyfob laser pointer is the best fiver you can spend!