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February 4th 04, 08:36 AM

Richard Clark wrote in message . ..
On 31 Jan 2004 07:42:00 -0800, (Maurizio) wrote:

However, the antenna that was simulated in the paper I was talking
about is a real antenna that has been modellized with a dedicated MOM
program and with the correct antenna geomety, and results have been
compared with measurements.
From this comparison it has been necessary the introduction of such
factor.
It seems to me that the 6 dB factor had to take into account all
losses from the transmitter to the radiated fields.
My concern is how this factor can be justified.
6 dB is a lot in terms of antenna usefull coverage distance.

Maurizio

Hi Maurizio,

I am a trained Metrologist with advanced studies in Microwaves. The
measure of power (which is intimately tied to any expression of dB) is
very difficult to achieve with great accuracy. This means that
measurements are always suspect when they purport to confound theory.

The logic of the MOM program that works at one wavelength expresses
that it will work at all wavelengths. There is no scale determinacy
whereby results in HF are corrupted in SHF. There is every potential
for human error and measuring power reveals that quicker than any
other effort.

A 6dB discrepancy is a human problem, and glaringly evident.

73's
Richard Clark, KB7QHC

Hi Richard,
I agree that the human factor can be the problem for this discrepancy,
however, it would be also very interesting to know about other
experiences with such type of measurements, just to narrow the
expected uncertainty window.
(Better if in presence of complex environments)

Maurizio