[Amps] Measuring RF Power

[Tomm Aldridge]

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?

Can we get back to AMPs and quit the belly bumping, please?

Tomm, KD7QAE