"Owen Duffy" wrote in message
...
On Mon, 17 Apr 2006 08:41:36 +0100, "Reg Edwards"
wrote:

You dim witts are calculating Q incorrectly.


Reg, that is just so polite!

Q = X / R

where R is the RF resistance of the conductor and X is the
reactance
of the conductor's inductance. You first have to calculate
inductance.


So, you state that the ratio X/R is an acceptable way to express the
Q
of an inductor, why is it unacceptable to express the Q of a two
terminal device with an equivalent series impedance of 0.88+j50
(where
0.88 is the RF series resistance of the network and 50 is the series
inductive reactance of the element) as 50/0.88 or 57?

Aren't the effiency implications (for that was the context) for a 50
ohm reactance created with a TL stub as described just the same as
for
a coil with 50 ohms of inductive reactance and 0.88 ohms of series
(RF) resistance, ie a coil with the same Q factor?

Owen
----------------------------------------------------------------------
---
Owen,
Please excuse my mild scold.

There is only ONE way to calculate Q of a coil or a wire and that is
the way I have described.

It is the ratio of inductive reactance to resistance of the wire, in
series with other. They cannot be measured in combination with each
other.

To do so results in something altogether different like measuring the
input impedance of an antenna at or near resonance where the inductive
reactance is tuned out by the capacitance and is therefore NOT
measured.

It is elementary my dear Watson.
----
Reg.