Hi, I've recently bought the GW Instek AFG-2225 signal generator but I'm dissatisfied with the fact the despite the promised 25 MHz square, for anything above 10-11 MHz or so the 'square' turns into a 'sine wave'. Yes, I'm measuring it using the feed-through 50 Ohm terminator on a 200 MHz scope. I believe this is because the rise time is quite high, 25 ns. The other generator that I considered is one of the Rigols and before I dump this one I have to be sure that a Rigol can meet my needs. Especially given the fact that it's hard to compare the specs and it may turn out that the general signal distortion at reasonable amplitudes is lower on the Instek than on Rigols.
Anyway, what I'd like to kindly ask you is to show me what a 20 or 25 MHz square wave looks like when watched on a 100+ MHz scope, when using a 50 Ohm terminator or the HighZ output option, at 3Vpp or more. Whether it truly is a square or maybe it also looks like a sine. The models that I'm interested in are: DG1022Z, DG1022A or DG1032Z.
And if by chance you also have some comparison between the Instek's and Rigol's AWG software for Win, please share your thoughts. Thanks!