Seeking to achieve the best frequency setting, broadcast stations often adjust their frequency emissions. This is also in response to the influence of weather conditions and the movement of sun spots.
所以目前國際廣播界，為了求得更好的聲音效果，常常要改換頻率，有時還必須因應氣候轉變、太陽黑子活動對電波的影響，而重新調整頻率。