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Old 08-16-2000
Mark Matthews Mark Matthews is offline
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Radio Signal Strength

What does the term five by five in a radio check mean, and where did it come from?

Mark Matthews responds:


The term five by five refers to the two measures of signal strength and readability; it is derived from older HAM radio instruments that were scaled from zero to 10 with 10 being the strongest.  A five by five would be interpreted as 50 percent signal strength and easily readable, perhaps with some static or band clutter. A 10 by two would have a strong signal, but be broken and hard to understand, while a two by 10 would contain a weak signal, but be perfectly clear.  A 10 by 10 would be very strong and crystal clear.

Mark Matthews