I will try. Decibels or db, when used in signal circuits are used to express a power level to a known reference level of 0db at known circuit impedance. 0db = 1 milliwatt @ some impedance. The impedance depends on the type of circuit. For CATV the impedance is 75 ohms, RF @ 50 ohms, audio @ 600 ohm’s, you get the idea.
Decibels are a log rhythmic expression of large changes in power levels. Forget the math but this ought to help:
0db = 1 mw
+3db = 2 mw
+6db = 4 mw
+9db = 8 mw
+10db = 10 mw
+20db = 100 mw
+30db = 1 W
-3db = .5 mw
-6db = .25 mw
-9db = .125 mw
-10db = .1 mw
-20db = .01 mw
-30db = .001 mw
Hope that helps… Dereck
