"Slotted?" To the point of being able to use slide vibrato on them? If so, your equipment is very good up there.
Question:
When you play a 12th partial Eb in 3rd position. the G, G#/A and A are to be expected...they are the 15th, 16th and...something resembling...the 17th partials. (After the 16th partials the overtone series turns into quarter tones.) Are there not an F of some sort and an F# above that Eb before you get to the G? There are on all of my horns, and that is the way the overtone series with Ab1 (Pedal Ab) as its fundamental.
S.



