power line termination for testing

[adeel.sid]

Need help to test power line channel impairments for different frequencies and cable length.
How can I terminate line if there is signal generator at one end?

 

[barry]

Maybe this is just too obvious an answer, but terminate it with its characteristic impedance. If it's a 50 ohm cable, use a 50 ohm termination; if it's a 75 ohm cable, use a 75 ohm termination.