AF, CPS, EHF, HF, Hz, MF, RF, SHF, UHF, VLF, audio frequency, carrier frequency, cycles, extremely high frequency, frequency, frequency spectrum, hertz, high frequency, intermediate frequency, kilocycles, kilohertz, low frequency, lower frequencies, medium frequency, megacycles, megahertz, radio frequency, spark frequency, spectrum, superhigh frequency, ultrahigh frequency, upper frequencies, very high frequency, very low frequency