Richard Clark wrote:

On Tue, 21 Jun 2005 22:25:32 +0100, Ian White GM3SEK
wrote:


When
there has been a reflection, the samples have opposite polarity and
cancel. When there has been no reflection the samples from that
direction of travel are in-phase and the sample total is double the
contribution of either sample.


Er, yes, pretty much...


Hi Ian,

To this point there is no controversy, no dispute. Why you should
hedge your assent remains elliptical and probably lies with what you
have to say following.


That's because it doesn't actually measure watts. It has been calibrated
in watts under certain specific test conditions, using a different kind
of wattmeter that actually does measure watts.


All power displays derive from some operations of an implied
mathematical operation and all power displays employ scaling. They
may, each, perform their job through different methods, but all such
methods are still abstractions that require transformation to a common
expression of power. There is nothing distinctive between these
methods (the only separable characteristic) that negates the others
results.

You are going to have to be more explicit about why the Bird's
expression of Power does not yield that characteristic.

I think the problem is not with the meter. The meter simply tells us,
based on several assumptions, how much power might be available to a 50
ohm load if the load were positioned appropriately at the meter
location. And, by making some additional correct assumptions, we can
accurately infer some things about the absorbtion of power at a remote
terminus from the measurements. In my opinion, the only problem is in
drawing incorrect inferences about the behavior of nature based on
readings taken from the meter, and from some of the less than fortunate
terminology which is associated with the meter readings.

ac6xg