On Mon, 16 Aug 2004 23:25:20 GMT, "Jerry Martes"
wrote:

What is a better way to measure an antenna's efficiency??

Hi Jerry,

I see you are suffering from answers out to three decimals again.

Your idea is not so far fetched, it is the simple calorimetric bomb.
With enough patience and references, yes, you could measure
inefficiency. However, the inefficiency could easily be lost in the
inaccuracy and patience is not a virtue where simpler methods prevail.

You rightly note that a total integration of all field strengths would
be required, and be far more cumbersome. This is the classic
treatment, but when done once with a reference for comparison, it is
unnecessary to apply to other antennas of simple characteristics.
Others note that simple comparisons serve quite suitably. For a small
antenna (that is, in relation to wavelength such as the DLM and others
like CFA/eh/fractals purport to operate efficiently in) there is no
hint that the radiation lobes are going to offer manifestly high gain
so as to drive comparisons off the chart. Certainly inventors make
such fantasy claims, and those claims characteristically remain
unsubstantiated. The DLM is a classic example.

Side by side comparisons of the DLM with known good antennas, or even
known poor ones with similar lobe patters could easily reveal
efficiency. I suppose these same inventors could crow about a razor
thin 24dB gain lobe pointed at the horizon (if you only knew the
tune-up procedures), but you are not going to find this from any
antenna packed into a box with less than quarterwave dimensions on all
sides. [readers: Examples proving this last sentence wrong are
welcome.]

73's
Richard Clark, KB7QHC