A new scope.. Well... At least it's new for me.

Hi, this is an update of my long time project. I finally got myself an oscilloscope. Well, technically I have had a real old one for some years but finally I have a DSO. Rigol 1052, there at the left corner atop of my old Russian cathode ray tube scope.

And my electronics desk needs some cleanup, too.

Rigol 1052 is over 5 years old model, so it's nothing new nor fancy. But it works... mostly that is. I got a good discount on this one, since the long memory (1Meg) is partially broken. As you see at the picture, the second trace has nasty noise overlaid atop of probe calibration signal.  I took some time to test the scope and noticed that there must be something really odd at the digital part of the system. Analog front-end and AD converters work just fine and the problem appears only at one of two channels. (see picture)

Direct capture of Rigol screen.

When I got the scope, I even took some time/effort to open it up and look if there could be anything obviously wrong at the board. But as far I could see everything looked like it should be. So, I just closed it back up and keep it as it is. In theory there could be a cold joint or short right under Atmel FPGA, that causes bad data to be moved to external ram. But it's highly unlikely I could do anything to fix the board here. So it's better to use the scope as it is and not break it any further.

Not much to see here.

All in all, the good thing is that this error does not appear at all if the Rigol is set using short sample memory. So, even though this scope has some (non typical, I may add) issues, it's still quite usable for  the needs I have. And the price was right for me, so I can't (nor want) to complain.