[Asterisk-Users] fxsmod cable length limit

[Rich Adamson]

> Is there a cable length limit to use with a fxsmod (TDM400B) ?
> I noticed that if I use a very long cable 148 feet, I can hear some
> parasite : I hear the radio ! If I use a short cable, there is no
> problem...

That use to be a fairly common problem with telephone lines years ago
when most were not yet buried underground. Two common ways to fix it
are: a) use shielded cable, or, b) install a .01 ufd capacitor across
tip and ring at both ends of the cable.

The capacitor is of a small enough value that its does not impact voice
or ringing.

The cable length limit is measured in 1,000's of feet, so 148 feet is
not an issue.