Question 6A451

Harmonic radiation consists of signals emitted at frequencies that are whole number multiples (e.g., 2x, 3x, 4x) of the intended operating frequency, known as the fundamental frequency. Therefore, statement A is correct. Since these harmonic frequencies are multiples of the fundamental, they will always be higher in frequency than the fundamental itself, making statement B correct. To comply with regulations and prevent interference, amateur radio operators must minimize harmonic emissions. Proper tuning of the transmitter's output stage, along with the use of external low-pass filters, effectively attenuates these unwanted harmonics. This makes statement C correct. As all three statements accurately describe aspects of harmonic radiation, "All of the above" is the correct answer.