109 prop pitch (rpm) and the supercharger

[pstyle]

Originally Posted by JtD

Prop and engine are linked at a fixed gear ratio and if engine rpm changes, prop rpm changes as well. For the DB 601 on the 109E the ratio was 1:1.55, so if the engine is at 2400 rpm, the prop is at 1550 rpm.

If this is the case (I don't know) the prop and engine RPM should be linked, so an increase in one results in an increase in the other.... in which case Crumpp's description appears to be contradictory.

Can we all specify exactly when we are referring to prop rpm, when we a re referring to engine rpm, and when we are referring to both?
That would sure help me understand.