I currently don’t have a BT Home Hub in front of me to try out and their user manual appears to be useless so don’t quote me on this.
You don’t need to use WPA Radius, there should be a setting for “WPA PSK” or “WPA TKIP” I think it’s the first one.
Set it for WPA PSK (if its there) and use a 63 character password. click here to get one!
You can use either the 63 random printable ASCII characters or the 63 random alpha-numeric characters.
Some wireless devices can not use all printable ASCII characters but most (if not all) can use the alpha-numeric characters.