[Amps] Measuring RF Power

[R.Measures]

On Mar 25, 2005, at 6:59 PM, Tomm Aldridge wrote:

> David Kirkby wrote:
>>> In any case, it would be pointless for me to try to answer your
>> question when nothing  is not defined properly.
>>
>> I mean nothing (P, I or E) are defined properly of course.
>>
>> But don't bother defining them for now - substantiate what you are 
>> saying.
>>
> All,  Some basic electronics follows.
>
> RMS Voltage or Current can be used to calculate power flow from a 
> linear
> element, such as a resistor or any other impedance not related to the
> value of the voltage or current impressed on or through it provided we
> know either value at each frequency component of the wave.  RMS voltage
> and RMS current may be directly multiplied to also yield power given we
> know them and we know the phase angle between the two at all frequency
> components of the wave.
>
> For non-linear elements, such as semiconductor junctions, vacuum tubes
> and such, Instantaneous voltage and current must be multiplied at
> discreet times and the resulting product averaged over a cycle of the
> complex wave to get the average heating effect.
>
> This method also works for linear networks but for single frequency
> sinusoids, we have become accustomed to taking the RMS shortcut.
>
> David, you are correct in your analysis.  Rich, lots of folks call what
> we get when we multiply VxI "RMS Power" so you are colloquially correct
> and technically inaccurate; so what?

Bananas
>
> Can we get back to AMPs and quit the belly bumping, please?
>
> Tomm, KD7QAE...

Richard L. Measures, AG6K, 805.386.3734.  www.somis.org