mojo wrote:It's quite surprising which 'scopes have the proper display algorithm and which don't. The Instek ones do, as do Tekway. Rigol and cheap Agilent stuff (which is made by Rigol) don't, but the big surprise was Tektronix which also don't display properly! Tektronix have a well deserved reputation for quality instruments, but it seems like they have really dropped the ball on this one!
All of the Tektronix scopes with a MB of memory or more have WaveInspector which allows you to see a proper representation of the entire waveform- including transient spikes- at the top of the screen. WaveInspector makes it trivially easy to find what you're looking for, and even faster to get to it. I've never found a situation in which it failed to show me even the smallest transient.
My guess is that they are playing catch-up with the Chinese manufacturers who have the advantage of starting out with FPGA designs that are suited to this kind of processing where as Tektronix use less generalised hardware that makes processing of large memories difficult. The arrival of affordable large memory 'scopes has forced them to offer similar features but they had to bolt them on to the existing hardware.
The MSO/DPO 2000 series was introduced in 2008 and was designed with full access to a FPGA's if they chose to use them. The particular problem you're describing has nothing to do with FPGA's though- the Tektronix scopes are capable of doing lots of calculations on their stored waveforms. If they wanted to utilize a different sampling mechanism they could easily do so. That said- I've spent a lot of time using WaveInspector and no changes are required- it does a better job that anything else I've used- including, recently, the Rigol scopes.
In those cases where you want more control, memory, or processing power- then you use Labview/Signalview on your nice big computer screen. All of the Tek scopes I'm aware of work with this software, and they do so effortlessly