I'm using the 40m lpf and the 20m lpf (positions 5 and 3 respectively). Although, I've double checked the values and the windings on the 40m filter, I've not checked the 20m one! Think I'd better take them all out and have a check, then test with just the 2 in place. (I've 80m in slot 0, 40m in 5, 30 in 4, 20 in 3, 17 in 2 and 15 in 1).
In fact I think I'll put a signal through them and have a look on the scope.
Thank you. It's nice to have someone else's thoughts.