In reply to a post by Anonymous:

get noise on the phone line when the router is connected

Then your filter isn't working... simples.

Just remotely possible it's the router, but new filters are a lot cheaper and more likely!

Got another filter and it seems to be a lot better.

Seems that I have 4 filters that have given up filtering BUT not totally just a bit.

Do the components in these things wear out? They just seem to be a small transforme,r a couple of capacitors and a couple of resistors but I suppose the capacitors could become less efficient over time.

Anyway thanks to everyone for all the help ;o)

Darren

There are good reasons why filters are cheap

I winder if you have had a spike/lightning strike on your phone line, which has affected all the filters plugged in at that time?

Transformer?