Interesting discussion on RF vs. AF. Well, RF once it gets into a wire does
not travel as fast as light.
And generally, we consider it RF if it retains its wave action of having an
alternating magnetic and electric field. While the AF is a varying voltage
without significant field components, due to its longer wavelengths. IF you
froze the AF instantaneously, it would look like a varying DC as compared to
its amplitude earlier.
At 14 kHz there is kind of a duality. 10 to 20 kHz was commonly used for
LF RF transmission in the days of Alternators used as transmitters. (The
Alexanderson, which was used by USAF as late as 1958, dating from the early
part of the century). Yet, 14 kHz is commonly seen in tweeters for AF,
producing a mechanical vibration with action of its transducer. The
Alexanderson Alternator produced an RF wave from its transducer, which was
the large antennas used with the old systems.
The most convenient distinction between RF and AF is the presence of both
significant magnetic and electric fields around the conductor of RF.
73, Stuart K5KVH
|