DaveC wrote:

Is it true that the higher the gain the flatter the "donut" shape of the
sensitivity field?

(And yes, my terminology is rudimentary... please forgive.)

I'm the one who initially committed than terminological crime so forgive
ME! Where is that big omni gain going to come from if not from the
vertical beamwidth? Start with the isotropic model pictured as a
spherical balloon. Squeeze it however you want to. Nothing about an
antenna can add volume to the model, its just a matter of how you
squeeze it.

-Bill