I wrote a study guide for the technician test, and since the question pool has changed, I decided to re-write it. The question pool has changed quite a bit. My concern is that the new question pool seems to contradict itself.
T0C01 - What is radio frequency radiation?
Answer, Waves of electric and magnetic energy between 3 kHz and 300 GHz
T2A06 - What is a radio frequency wave?
Answer, Electromagnetic oscillations or cycles that repeat more than 20,000 times per second
T7B07
What is the lowest frequency of electrical energy that is usually known as a radio frequency?
Answer, 20,000 Hz.
There's quite a difference in 3kHz and 20kHz, the 2 lower limits for rf, and even more difference in the upper limits, 300 GHz and infinity.
Well, that's my 2 cents worth!
bruce