Coax to RJ11 FREE cabling and networking Helpdesk
 Question by David Weintraub posted 18 Sep 2005
 Coax to RJ11
I have dsl service and I have my computer in a room with no phone jack but there is a cable tv jack (coax) in the room that has not been activated by the phone company. Since this jack is not hooked up and has no signal in it, I wanted to know if I could run the phone signal through it, connect it to my dsl modem and still have a good quality connection with no danger to the dsl modem? On the outside of the house, the telephone and CATV boxes are next to each other. I would have to run a connection from the phone box to the now un-connected coax cable. Any help you can offer is appreciated. Thanks. David Weintraub
 Answer by Joseph Golan posted 19 Sep 2005
Dear David,

DSL and telephone signals are meant to run on balanced twisted pair with an impedence of 100 ohms. The coax for cable TV has an impedence of 75 ohms and coax is considered unbalanced.

I cannot predict what will happen to the DSL signal if you attempt this.

As far as danger to the modem, as long as all the cabling has the proper protection, I cannot envision what danger there would be.

My suggestion is to have a new cable run for your DSL service.

Joseph Golan, RCDD

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