Richard Fry wrote:
. . .
The greatest improvement in that performance will be achieved when the
intrinsic E or H gain of the receiving antenna matches that of the
radiated EM wave (in the US, or elsewhere).

What's "intrinsic E or H gain"? In what way does it differ from gain
calculated relative to an isotropic source? How does one calculate the
gain of an EM wave?

Roy Lewallen, W7EL