Keith Dysart wrote in news:1177719266.182305.327520
@l77g2000hsb.googlegroups.com:

On Apr 27, 7:36 pm, K7ITM wrote:
Grrrr. I'll try to
remember to check the couple of books I have that would talk about
phasors to see if I'm misrepresenting them, but I'm pretty sure they
are equally explicit in defining a phasor as a representation of ONLY
the phase and magnitude of the sinusoidal signal, and NOT as a vector
that rotates synchronously with the sinewave.

My recollection is of being introduced to phasors with the study of
electric machines which have real rotating magnetic fields. By
jumping onto the rotor and rotating with those magnetic fields,
solutions became trivial by allowing vector arithmetic on the now
stationary phasors.

Isn't hopping onto the rotor (assuming synchronous speed) to make your
observations called moving from the time domain to the frequency domain,
and all the mathematical shortcuts are only valid if all quantities share
the same angular velocity (or frequency), implying sinusoidal waveform.

I guess a departure from the strict phasor environment is for example
when we consider a noise vector rotating about the end of a carrier
phasor in exploring FM detector S/N vs C/N.

Owen