Why RF radiates but AF not?

-RF radiates on antenna but why AF (audio friq) not?
-How and why RF can radiates surprisingly in single rod in whip and in different separated rod in dipole? Why RF is such special?!

I don't think your premise is correct. You can pick up 60 Hz hum from power lines. Here another link you may find interesting: http://www.vlf.it/trond2/below10.html

Extremely low frequencies have very long wavelengths. That is/was used to advantage in the LORAN C systems. The transmitting antennas were quite long.

John

John, LORAN C is still in use?

There was a site on the next island over (part of the US Atlantic Coast coverage) but it was shut down, oh, I guess 15-20 years ago.

The USCG discontinued LORAN C transmissions in early 2010 (https://www.navcen.uscg.gov/?pageName=loranMain). That is the reason I used the past tense in my response.

John

Ok. I see. It was the present tense that threw me...

This is not a simple question to answer on a forum.

The amount of energy radiated is down to frequency. e=hF, energy = Boltzmann's constant x frequency.

As frequency is directly related to wavelength, the effiency of a radiator is down to its length as a radiator c/w its wavelength.

VLF transmitters such as Loran and time signals such as DCF77 and MSF60 require huge lengths of aerials to radiate in any terms of efficient. Due to propogation properties (a degree in itself) they can travel hundreds of miles. They tend to be known in the UK as aerial farms where vast wire lengths are run over many Km in total.

GSM at 900MHz/1800MHz in the UK is a much shorter wavelength and can radiate quite efficiently in an aerial a few cm long but cannot propagate more than a few tens of miles due to many reasons including atmospheric absorbtion, earth curvature.

50Hz/60Hz radiation tends to be magnetic coupling as the radiating elements of the wires is far too short to be efficient.