Formulae

Quick reference.

Power

dB = 10 log 10 P in P out
Table of ratios (Power in / Power out)
-----------------------
1	0 dB	 no loss
1.05	0.22 dB  (5W loss)
1.11    0.46 dB  (10W loss)
1.25	1 dB     (20W loss)
1.33	1.25 dB  (25W loss)
1.50    1.74 dB  (33W loss)
1.66	2.2 dB   (40W loss)	
2	3 dB     (50W loss)
3	4.8 dB	 (67W loss)
4	6 dB	 (75W loss)
5	7 dB
10	10 dB
20	13 dB
50	17 dB
100	20 dB

Reactance

Xc = 1 / 2 * pi * f * C
Xl = 2 * pi * f * L
Back