RG-62 as a vibration probe.

That I'm not so sure about. The fiber is by the railroad track because railroads have god-like power, at least in the US. They can do pretty much what they want in their right of way, so it is easy to lay fiber when you don't need to get approvals.

If a railroad crossing causes traffic problems, it is up to the town to build an overpass. The railroad right of way is supreme.

Good unless the RF can be detected.

Finding the location using the bend might work, but it would have to be quite the bend to cause any significant reflection. Normally bending just scatters light out into the cladding.

Cheers

Phil Hobbs

Used to measure speed of an object, in my case small motor cycles.

We used coax strung across a test track in a similar fashion to those pneumatic car counting strips. The output of the interface circuits drove a transistor across the start & stop buttons of some bench style stop watches.

Jumping in late here, but I had a run-in with RG-62 in a previous existence. There are two versions, possibly one of them is RG-62B. One version is designed for wide bandwidth (i.e., low loss at high frequencies.) The other is designed to keep digital transitions from "smearing out" (i.e., good phase linearity). Be sure you have the correct type for your application!

Nico Coesel schrieb:

Hello,

but what about Hanford Site and Columbia River?

Bye

Who knows. I was at a "government expo" and the system was being displayed there. They claimed to be able to put the fiber in a fence and detect where the fence was "disturbed." This was high end security, the kind of technology bought by governments, not the great unwashed.

I think it was some company owned/funded by BAE. You know how the defense business goes. When you dig deeply, there are not a lot of players.