Dave, a normal one is a £3.95 job that you use for a normal plug in phone.

Just for interest, see:

http://www.adslguide.org/newsarchive.asp?item=1777

I think the clarity ones are the best option for alarms as alarmgard said. It allows you to hard wire everything.

Stay away from filters from EBay especially when using them with alarms.

I also find that standard plug in filters are more likely to die on you that the hardwired faceplat ones.

just put an order in today to ACT for 2 of the ACT-431 DSL Alarm Filters,

to try out next week at customer premises.

I'm sure i read somewhere signals will still be received by cs even without a filter.

Funnily enough i spoke to a customer today on the fone re: this very problem and apparently he was told by another engineer to put his system on test with cs and press the pab, then phone up cs to confirm sigs. He carried out this exersice and low and behold

NO SIGS RECEIVED.

So i dont know yet how true this is until I send My eng out next week to to fit the ACT filter and get a report from him.

Amazed that he is quite happy without any signalling until next week.

Will post again with an update week after next, as away to sunnier climes next week.

c ya.