Right-on about the circuit simulation to model filter performance. Even back in university it was practically impossible to get the exact same results on a multi-element filter build.
I had one prof who would knock down your grade if the measured filter curves did not match the model. I spent many a late night in the lab poking and prodding winding spacing. He really only looked at turns counts. I was tempted to build him one with Litz wire just to give him a fit, but i needed the good grade.
--
Tisha Hayes, AA4HA