[Elecraft] Noise Blanker

[Rick Wheeler]

How can one tell if the Noise Blanker is working OK? I live in a
relatively quiet (RF that is) area with an occasional electric fence or
household generated noise. But no matter what I do (Lo Thr, Hi Thr,
nb1, nb2, or off) I can not detect an inkling of difference or
attenuation of man made noise. I can generate noise with a hand-held
drill or garbage disposal and no difference is detected with the noise
blanker on or off. 

I am familiar with the types of noise (at least the types listed in the
Noise Blanker manual) the Noise Blanker is supposed to suppress. Is
there any other common device I can use to "test" my Noise Blanker?

Rick
K4LX