yeah, take a look at this photo
there should be 25 data points per trace per division, instead there is about 10. there's also a slope change once the blue trace gets to 48 volts, it starts climbing slower. it should reach all the way to 60 volts. the hook in the yellow trace should be lined up with the bottom most ring of the blue trace.. which has a real life frequency of 50Mhz.
instead the blue trace is delayed 5ns, and the scope shows that its frequency changes!... which i know is not the case, it should ring down like any other smps.
the only difference between my scope and the 1102E is the memory depth and the screen size.
another issue is crosstalk. note that the blue trace is lifted 1-2 volts while the yellow trace is falling.
but also note that the oscope isn't sure about that so it waits half a division before displaying this "lift"
in real life there is something there.. its on the order of negative 10 milivolts plus the inductance of the current sense resistor.
so you should see a spike on the blue trace on the order of -1 volt for like 5ns, then it should fall to zero, then stabilize at -10mv (these numbers are relative to the voltage drop across rds on before the gate is pulled to zero)
(one half amp of gate drive through a 20mohm resistor with an inductance of say 5nH)
another issue is lack of significant digits on such things as volts rms. (no surprise, 8 bits is only 8 bits.)
so you might see 60 volts rms displayed, or 61.44, or 60, or 61.44.. it doesn't know how to do a true rms over more than one line cycle i guess.. because that should average out to better than 8 bits.
another issue is the fft only calculates what is on the screen, not what is in the memory. the screen being 234 pixels high rather than 256 means that there's data loss somewhere between the 8 bit ADC and the screen. i've verified this by adjusting the signal so it is just barely clipping on the screen, but should still be below 256 bits wide, the fft and the rms measurements displayed will change.
there is also no warning about this data loss.