Wireless interference question

[TechSupp]

Just had a wireless rounter installed at my Dads for his laptop and he has cordless phones as well on the same telephone point filter adaptor. There is interference in the phone when the phone line cable from the router is plugged in (router powered on) but not when its pulled out so dont think its due to the wireless of both. I know this can be a problem but would think the interference would still be there if the router was powered on and the telephone cable from it unplugged. Any ideas what I could do to reduce the interference. You can still use the phones and wireless its just there is extra background noise when using the phone and his hearing is not always that good. Cant change where they are positioned due to power and telephone socket restrictions/availability.

[computer_expert]

Have you tried changing the channel that the router's wireless network broadcasts on?

[john]

Have you tried a different microfilter? I had something similar and swapped the filter and its been much better since.

[TechSupp]

Going to try a different filter and move it to a different socket (just remembered he has sky and a new socket was fitted for that!) See what happens then. Thanks for the suggestions.