I don't think that things are quite as clear cut in real life as your post implies.
It is true that certain combinations of VOR, receiver and Propeller will interfere with one another at certain RPMs. The symptoms normally take the form of needle oscillation rather than an apparently sound, but false indication.
I've never heard anybody advance a theory about the precise RPMs at which this occurs, but I would be surprised if the relationship was quite as straightforward as your post implies. The most likely cause, I would think, is RF harmonics from the engine and/or associated ancilliary gear which would not presumably occur at evenly spaced prop RPM intervals.
2D