Radio waves have the longest wavelengths in the EM spectrum, according to NASA, ranging from about 0.04 inches (1 millimeter) to more than 62 miles (100 kilometers). … Bands of radio waves. BandFrequency rangeWavelength rangeHigh Frequency (HF)3 to 30 MHz10 to 100 mVery High Frequency (VHF)30 to 300 MHz1 to 10 mWhat Are Radio Waves? | Live Science www.livescience.com › 50399-radio-waves