Henry Kiefer wrote:
. . .
But I miss something. Maybe something with differences between transmitting
and receiving with a ferrite antenna. The antenna is not pure reciprocal -
because the ferrite (or iron powder) can be nonlinear!

1. Ferrite and powdered iron are entirely different materials, with
different physical and magnetic characteristics. Powdered iron isn't a
good choice for this application.
2. You're not likely to drive either one into a nonlinear region when
they're in the form of a rod because of the large air gap in the
magnetic path.

Roy Lewallen, W7EL