Guys, you're off on a tangent!

I believe Efficiency is the ratio of power radiated to power input.

If a dipole is 95% efficient it radiates 95 out of 100 watts.

If a Yagi is 95% efficient it radiates 95 out of 100 watts.

If a Quad is 95% efficient it radiates 95 out of 100 watts.

If a vertical is 95% efficient it radiates 95 out of 100 watts.

If a Log Periodic is 95% efficient it radiates 95 out of 100 watts.

If a 1/10 wavelength antenna made of unobtainium is 95% efficient it
radiates 95 out of 100 watts.

Don't confuse Gain, Directivity and Efficiency in the discussion.

Deacon Dave

Richard Harrison wrote:
Art, KB9MZ wrote:


SNIP

In any case, "efficient" is only as compared with similar devices.

SNIP: Wrong!! See above

Recall that dBd is the norm as an isotropic antenna is only a
theoretical creature. Catalogs are filled with antenna characteristics
as compared with a 1/2-wave dipole in free space.

SNIP: The comparison is generally Gain as dBd, dBi, or dBu
[unobtainium]. Not Efficiency!!!

It is the standard of
comparison. It could hardly be correctly called inefficient.

Best regards, Richard Harrison, KB5WZI