HAM Radio 101

Word of the Day (QRM): What is QRM in Ham Radio?

What is QRM…and why do so many Ham Radio abbreviations start with Q? Let’s answer the latter first. Original Q Codes (45 abbreviations beginning with the letter Q) were developed in the early part of the 20th century by the British government for use by ships and coast stations so maritime Morse operators speaking different languages could better communicate. Both QRM, “Are you being interfered with?” and QRN, “Are the atmospherics strong?” are still common abbreviations used in Amateur Radio. Today, QRM stands for human-made noise, as opposed to QRN, which indicates noise from natural sources. If you hear an operator say, “I’m getting some QRM,” it means there’s man-made interference affecting your transmission.

Equipment, such as DX Engineering’s NCC-2 Receive Antenna Phasing System or WiMo’s QRM Eliminator, are designed to null out QRM from sources such as power lines, lamp dimmers, motors, and other electronics.

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