zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
A SLC (Subscriber Line Concentrator) is basically a box that takes fiber on one side and spits out POTS lines on the other. If they're too close to the CPE, the lines can have all kinds of interesting problems, just like the ones you've been seeing. Usually the problem is either really high loop current since the line is only a few hundred feet long, not a few thousand, or the audio signal is too high. IIRC both of these are programmable, but it takes a clueful person at the telco to do it. (Also, the SLC can be over provisioned, on the POTS side, which means that if too many people pick up the phone some of them won't get dialtone since all the channels are already in use). Oh, and a SLC usually won't drive the line all the way up to 54v.
For excessive loop current problems, you can get one of the handy loop current devices from sandman, insert a maybe 1k resistor in each wire, or 'extend' the line a thousand feet or so with an old spool of 24g CAT3
. The latter is usually the easiest.