Chiff and Fipple Forums

Just a thought then - if the 'step' created in the tube of a tuneable whistle affects the sound and intonation, does it then not logically follow that a non-tunable would be free of problems/issues which a tuneable might have, since it's an uninterrupted tube?

It might well, and I have indeed considered it as very likely affecting one brand where I've owned and sold on tunables but merely heard non-tunables.