Wayne Parham Messages: 18748 Registered: January 2001
Illuminati (33rd Degree)
If you have a signal generator and scope, simply use a series of frequency points and measure the input and output voltages. This will allow you to plot a graph, which you can calibrate in linear voltage or in decibels. You'll probably want to scale with decibels, so convert voltage to decibels using the formula dB = 20log(Vout/Vin).