On Nov 13, 5:16 pm, Roy Lewallen wrote:


That's the gain of an NBS Yagi in free space. It's more like 13 or so
over ground, depending on height and ground characteristics. Comparing
the gain of one antenna over ground to another (for example a dipole) in
free space is a trick often used by antenna manufacturers to fool naive
people. Both must be in the same environment for a comparison to be
meaningful.

Roy Lewallen, W7EL

I missed the part where he said it was modeled 23 m over ground..
But then you have to wonder about the ground quality used.
Thats why I always quote antenna gain using free space numbers..
I often forget that some people don't always do this... :-/
Gives a level playing field that works for anyone no matter where they
are.
I never quote gain numbers including ground effects unless I
specifically
mention it due to some reason. And thats very rare. So I tend to
constantly
think in terms of free space gain most of the time if I'm thinking or
talking
about antennas not mounted in any specific location.
One can always add the effects of ground themselves if they desire
that
for their local QTH.
MK