Panasonic 6.0 Series 3 Handset Cordless Phone

I bought this phone to replace several individual phones we had around the house.I liked that only the base unit handset had to be plugged into the phone jack.Unfortunately it sounds better in theory than it actually works.I have noticed and echo and cracking in the phone if you are using one of the extension handsets.The directions stated you could use it upstairs and downstairs in your home.We can not use a handset upstairs.It's like it's not getting the connection from the base unit that is downstairs.This should not be the case.It's not like I live in mansion or anything.I am mad that I wasted my money on this phone system.It is not one I would recommend unless you are using it within a few feet of the base unit.