Reg:

When ever you see charts being drug out and used as the basis for what
one is doing--you know you are in trouble.

Either the underlying laws and mathematical functions of that in
question are severely lacking--or the people you are dealing with do not
have the necessary skill--usually the former... here in radio you find a
lot of the latter...

From the abundance of charts laying around--I'd say there is still about
1/2 not known!

Warmest regards,
John



"Reg Edwards" wrote in message
...
When it comes to measurements, most amateurs and very many
professionals suffer from delusions of accuracy.

Making measurements is an ART rather than an engineering discipline.

ALL measurements are subject to error. Errors are distributed in
magnitude between trivial and catastrophic. Much of the art lies in
assessment of the magnitude of error and depends on the
measurement-makers' judgement and experience. Indeed, honesty is a
factor.

To gain support for the validity of a measurement result by stating
the manufacturer's name and serial number of the instrument used
doesn't carry much weight since accuracy depends on the person who
made the measurement and many other just as important factors. People
can't be avoided.

Something similar applies to numerical computer programs. The
reliability of a computer program depends on the programmer's
knowledge of the matter in hand and has nothing to do with the machine
it is running on. Far too much faith is placed on computed results
merely because they are computed.

Very little extra knowledge is gained by comparing a pair of computed
and measured results because there is no means of knowing how and from
where the inevitable difference arises.

Reliabilty and confidence of both programs and measurements require
time in which to accumulate. Mean time between estimated errors?
----
Reg, G4FGQ