Ian White GM3SEK wrote:

And here you've made that big leap again. Where did "power" come from?
Nothing in what you or I have said above explains how come the meter can
read "Watts".

It is calibrated in watts assuming that:

Vfor^2/50 = Ifor^2*50 = Vfor*Ifor = forward power

Vref^2/50 = Iref^2*50 = Vref*Iref = reflected power.

This is in accordance with the laws of physics embodied in the wave
reflection model. '50' in the above equations is critical. In any other
environment besides 50 ohms, the assumptions are not valid and the
calibration will be in error.
--
73, Cecil http://www.qsl.net/w5dxp

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.

73's
Richard Clark, KB7QHC

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

On Wed, 22 Jun 2005 10:32:36 -0700, Jim Kelley
wrote:
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.

Hi Jim,

This is the legacy left to all measurements being used. None has any
absolute authority, nor is any measurement a truth in isolation.
Further, without a statement of accuracy or context, no measurement is
even valid of anything in particular.

Behavior is demonstrable, or exhibited. It is measured by perception,
or by fine grain tools such as meters (which are pathetic in
comparison to the eye, ear, or sense of touch for range AND
sensitivity). Behavior that is not demonstrable is the enigma of
ethics. Would you steal if no one is watching?

I am fully aware of the sub-text of trying to divorce the Bird
Wattmeter from the discussion of waves. However to say it does not
measure power necessarily pollutes all instrumentation with the same
bias of argument. Hence this logic must eventually devolve to no
instrument measures power - or waves - or what have you. Rather
pointless in the end.

73's
Richard Clark, KB7QHC

Cecil Moore wrote:
Ian White GM3SEK wrote:

And here you've made that big leap again. Where did "power" come from?
Nothing in what you or I have said above explains how come the meter can
read "Watts".

It is calibrated in watts assuming that:

Thank you, Cecil: those key words "calibrated" and "assuming" are
exactly what I wanted to bring out.

Vfor^2/50 = Ifor^2*50 = Vfor*Ifor = forward power

Vref^2/50 = Iref^2*50 = Vref*Iref = reflected power.

This is in accordance with the laws of physics embodied in the wave
reflection model. '50' in the above equations is critical. In any other
environment besides 50 ohms, the assumptions are not valid and the
calibration will be in error.

So the printing on the Bird scale depends on a calibration using a
different kind of wattmeter - one that measures real RF power delivered
into a 50 ohm load. But beyond that, the calibration for a mismatched
load depends on a large additional helping of theory.

Those are the reasons for the point I'm always wanting to make about the
Bird: it cannot be called in evidence to "prove" anything about forward
and reflected power, because it is entirely dependent on the theories
under debate.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

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

I was giving Richard H the chance to notice that wasn't quite correct,
that's all.


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.

Simply because the theory that converts the Bird's raw readings
(actually rectified RF voltage) into "Watts" on the printed scale is the
very topic that is under discussion.

That means the Bird's readings of "watts" cannot be called as evidence
in the debate. Any argument based on doing so is doomed to be circular.
It *may* still be correct, but that cannot be proved through a circular
argument - you have to find some other way.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Jim Kelley wrote:
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.

Spot-on, Jim.


Oscar Wilde: "I wish I'd said that!"

James McNeill Whistler: "You will, Oscar, you will..."



--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Ian White GM3SEK wrote:
Those are the reasons for the point I'm always wanting to make about the
Bird: it cannot be called in evidence to "prove" anything about forward
and reflected power, because it is entirely dependent on the theories
under debate.

But that makes you a little like the people who believe that man has
never walked on the moon. No amount of proof is ever sufficient. And
indeed, 1000 years from now, most of what we think we know now will be
obsolete.

So all we can do is operate within the laws of physics as we, the human
race, understand them to exist at the present time. The debate is
underway.

Can photonic wave energy "slosh" around side-to-side at sub-light
speeds?

Can the laws of physics embodied in the wave reflection model and
conservation of energy/momentum principles really be considered to be
"gobblygook" after faithfully serving man during a century of
scientific discovery?
--
73, Cecil http://www.qsl.net/w5dxp

On Wed, 22 Jun 2005 19:44:33 +0100, Ian White GM3SEK
wrote:

That means the Bird's readings of "watts" cannot be called as evidence
in the debate. Any argument based on doing so is doomed to be circular.
It *may* still be correct, but that cannot be proved through a circular
argument - you have to find some other way.

Hi Ian,

You have simply invalidated any method to prove the debate. In a
sense, yours is an appeal that nothing can be known and hence nothing
can be proven.

Yes, I know this may be "inflammatory," but I would counter: give me
one method of determining power that does not eventually appeal to
circular definitions.

This, of course, comes at the risk of starting yet another endless
round - pun deliberate.

73's
Richard Clark, KB7QHC

On 22 Jun 2005 12:02:38 -0700, "Cecil Moore"
wrote:
Can photonic wave energy "slosh" around side-to-side at sub-light
speeds?
How many errors can you count here?
where the number of words = n
n!