Frank wrote:
On 5 Mar, 20:41, Roy Lewallen wrote:
I should elaborate a little.

The average gain is the ratio of the total power in all directions at a
great distance (beyond the point where the surface wave has decayed to a
negligible value) to the power into the antenna from all the sources.
(There's a factor of two also involved when using a ground plane with
NEC but not with EZNEC.) So the average gain is the efficiency if you
consider ground reflection and the decay of the surface wave to be part
of the loss.

"Ground reflection loss" is probably a more precise term.

Yes, that is what I meant and what I should have said, instead of just
"ground reflection". Thanks for the correction.

Roy Lewallen, W7EL