NEW Keysight HD3

[Someone]

Perhaps instead of hints, suggestions, and talking sideways you could say what is the actual problem you face?

Keysight 1000x, 2000x, 3000x. I have no problem setting a 1kHz low pass filter and seeing a clear waveform from higher frequency PWM. It can be set for lower frequencies such as 10Hz or 1Hz if needed. In high res mode you even get 12bits of resolution and can zoom in. I would expect the HD3 is similar and better.

I wrote that I couldn't get 1khz cut-off frequency with the filter functions, neither with Siglent, nor Rigol, nor Lecroy.
Unfortunately, I don't have Keysight available, but if it works there without any problems, I would like to have that too.

You said the opposite previously:

On my former rigol mso 5000, four math channels at the same time are traceable, without any remarkable slowdown of the system.
Also the rigol got digital filters(HP, LP, BP, etc...) as math functions.

I´ve used them for displaying a 3-phase sine from a 3-phase pwm signal.

Or is the 1kHz some important limit which although some scopes do have filters you could not get to 1kHz in some combination of other settings? You have not explained the problem, Siglent 2000 HD has filters so why are they not able to produce a 1kHz (or approximate) cutoff?

[Martin72]

I couldn't get the 1kHz to work, as mentioned twice before.
1kHz would be "ideal" insofar as it represents the cut-off frequency of the output filter in the real device.
Of course, if you "get down" to 5khz, the signal will already look sinusoidal.
With the filters offered by a Siglent, you cannot reach this lower cut-off frequency with a certain time base.
I didn't get that with the Rigol either, but it's reasonably close.
I can demonstrate this next week, or egonotto is kind enough to do it beforehand:
https://www.eevblog.com/forum/testgear/magnova-oscilloscope/msg5662657/#msg5662657

[egonotto]

Hello,

Bad__Driver gave me a hint to look in the manual of the SDS3000X HD.
There you can read that you should switch on “adaptive sample rate”.
If you want to set a certain cut-off frequency fg for the low-pass filter, the sample rate must be between 4*fg and 100*fg.
At 1 kHZ cut-off frequency, the sample rate must therefore be between 4 kHz and 100 kHz.
At a cut-off frequency of 10 Hz, the sample rate must be between 40 Hz and 1 kHz.

@Someone: What are the conditions for the sample rate for Keysight 1000x, 2000x, 3000x if you want to set the cut-off frequency of a LP filter at 10 Hz?

Best regards
egonotto