spdif 75 Ohm question

[Yasoo]

So I'm supposed to use a 75 Ohm cable for my spdif on my audio cards. I have some RCA type connector cables and I don't know what the Ohm rating is. Is it a proper test to check the resistance from tip to tip to check for 75 Ohms?

 

[Track Rat]

You can't measure it that way. The 75 ohms refers to its chartecterictic impedence and not an actual DC resistance. It's a function of the diameter of the center conductor, the diameter of the outer conductor and the distance between the two. RCA cables that are for connecting up stereo components should NOT be used. If its a video grade coax terminated in RCAs, that's what you want.

 

[Yasoo]

O.K. Thanks.