Ok so my wife bought me a Sain Smart DDS 120 PC based oscilloscope for xmas. I am running it on a mid 2010 MacBook Pro through parallels and Windows XP.

To be honest this is totally new to me. I have never used one at all. I just set it all up and finally got it running. Now When I try the test signal from the square tab on the unit sometimes I get a square wave on the screen sometimes I don't.

I am just curious as to what settings guys that are using a device like this are using? And or any tips on using it in general?

Thanks in advance....