Topband: Phase and Polarity -- They are Very Different

[Tom W8JI]

"Phase inversion" is a long used term for inverting the phase of any signal. 
It appears with discussions of push-pull amplifiers, and it is equally used 
in RF phasing systems.

Phase inverter and phase inversion even made it into the Communications 
Standard Dictionary as "a device that has an output analog variable that is 
equal in magnitude to its input but of opposite algebraic sign."

It appears in textbooks back to the earliest I have.

Google it:

http://en.wikipedia.org/wiki/Phase_inversion

http://www.300guitars.com/articles/article-demystifying-the-phase-inverter/


> At the risk of being a PTA, let me remind all that phase is a continuously 
> variable quantity that is directly related to frequency and time. It 
> cannot be "inverted" or "reversed."

This might be a recent jargon thing in the high end audio world, because 
textbooks, dictionaries, and common use accept the term "phase inverter" and 
"phase inversion" as related to signals, and they have since long before we 
were all born (unless some of us are over 100).

If someone said "polarity inverter" to me, I would think of a DC system. I 
wouldn't have a problem with "phase inversion" of time varying analog or 
digital waveforms, and would instantly know exactly what they meant.

73 Tom