So, this is a negative pulse generator. It's used for the detection of communications which are not transmitted on Hz waves, but rather in Sine waves. The machine generates a negative sine pulse, and if it were to receive a positive pulse, the bar on the screen would begin to waver in a sine wave.
It would be used by paranoids with deep pockets(I'm not going to let these things go for just pennies....), people in militias, and just other general nerds/fringe people.
I think that it's pretty neat, and that there should be one in every town in the middle of the woods, it's useful.