Reed wrote:
Mikepier wrote:
Trying to troubleshoot what I thought was a basic problem. A DSL
modem installed in a construction trailer not working. There is a 6
pair outdoor phone cable feeding the trailer from the main building. 5
phones work perfectly fine in the trailer. For some reason I can't get
the DSL "happy" light to light up on the modem in the trailer. I
tested the modem inside the main building just before it leaves the
building and it worked fine. I swapped pairs on the outdoor cable, but
no help.
I know distance is not an issue because I tested that too. I "looped"
back the DSL line back down to where it comes in main telephone room
( basically doubling the distance) and it works fine. So I'm thinking
this is more of an inteference issue. Any ideas where to start? The
trailer is next to an MRI facility, not sure if that matters.

What is distance from main bldg to trailer ?? Could you leave modem in
main bldg and extend the Ethernet cable to the trailer ??

or wireless WiFi ??

Not the best, but could be workarounds.
I think you are on the right trail with interference idea. Bringing it
back in on the other pair and having it work fine means the cable is
okay. (The cable twist cuts down the interference.) Is there a good
ground connection on the power out in the trailer? Can you string a
couple extension cords from the building during off hours and try
different power? Could be the MRI unit- those throw off EM and RF like
mad. Ever seen how funny the video looks when a TV station tries to roll
tape in the room when it is running? Just for giggles, I'd try a long
extension cord and a long cat5 cable, and see if the modem and computer
work in the cab of your truck as far as you can get from the MRI building.

You could always line the trailer with expanded mesh or even chicken
wire, and make it into a Faraday cage... :^/