Hands Free Home Phones Not Working

[#1]

None of my hands free phones work with the router plugged in, to make a call I have to unplug the router? Any suugestions appreciated!

[#2]

Do the normal phones work
When you unplug the router is the hands free phone plugged into the filter or direct into the socket

[#3]

That sounds as Jim says as if either the router or the phone connection to the line isn't filtered, so the ADSL noise on the line is disrupting the calls. If it's not that then possibly the phones use a similar wireless bandwidth to the wireless signal coming from the router so changing the wireless channel (or turning off the wireless, if you don't use it) might sort it?