David, you are doing a lot of reading of different posters and then
placing them under my name. I have no idea of what you are trying to
project with this accumulation of various postings from various people
tho I cqan see that you are getting mad as hell over something.
cool down

Dave wrote:
art wrote:

Dave wrote:

If a simple dipole is fed with 100 watts and radiates 95 watts, it is 95% efficient.


David if you had a dipole that had inherrent directional capabilities
would you consider
that as a possible choice for better efficiency ? Where does the 95%
number come from and where did the 5% go so. Did turners post influence
your guess at that number? is he worth copying? Others can get an idea
what you are talking about ie. parameters of use for which you are
applying the 95% figure to. It is possible that we can at least one
negative from the discusion in search of the kernel of info. Does the
dipole become more or less efficient as it moves away from its design
frequency as it becomes "detuned" Give me some meat

SNIPPED

Art, It has absolutely NOTHING to do with measurements, or with 95 watts or 5
watts, or antenna patterns, or the reactive components.

It is defining efficiency properly!

Net radiated power divided by power input is Efficiency. Measure it or calculate
it any way you want!

An antenna with -3 dB loss is a 50% efficient antenna independent of the actual
input power. Choose any power input you like. An antenna with -3 dB loss is a
50% efficient antenna regardless of gain, directivity, antenna patterns,
patents, claims, marketing Bull S--t, or anything else.

Put your favorite antenna inside a sphere of any suitable diameter that contains
the antenna. The total rf power coming out of the sphere divided by the total rf
power into the antenna [sphere] is the antenna efficiency. There is NO OTHER
definition!

Reducing power in the back and side lobes has absolutely NOTHING to do with
efficiency. It has to do with directivity.

Design of a Yagi, traps, conductors, element spacing etc. will produce
variations in gain, directivity, efficiency [variations in losses, heat].
Practically, the difference in efficiency between a 90% efficient antenna and a
98% efficient antenna is swamped by variations in the path loss physics.

I spent years of my life designing rf systems for telemetry from space vehicles
through reentry to a ground station. Data integrity at the ground station was
and still is the dominating requirement. Based on allowable data error rates,
the total path equation required S/N ratios of 12 dB or more. The solution is a
systems solution where the minor variations in antenna efficiency get lost in
the calculations.