I tried a spectral analysis of SDS824X_HD_Binary_C4_1.bin (as posted by Performa01, 100M points, 2GSa/s, 500µV/div) with Welch's method (2M window size, 80% overlap), and it results in a very similar shape as the SDS824X_HD_ND_2GSa_1mV screenshot (although calculated from a different data set).
[ PS: The plot is just calculated from the raw sample values, so the absolute vertical scaling is not yet correct.
I was too lazy yet to find out how to find the scaling factor from raw sample values to Volts in .bin file header. ]
EDIT: Does anybody know the "code_per_div" value for the SDS800X?
The value 25 from the following paper obviously applies only to 8-bit samples.
https://siglentna.com/wp-content/uploads/dlm_uploads/2021/09/How-to-Extract-Data-from-the-Binary-File.pdf
Is it 256*25=6400 for 16-bit samples? (just a guess)
Thank you very much for your effort!
The binary file should be in "V4" format, as described in chapter "SDS2000X HD | | SDS5000X After 0.9.6 | | SDS6000 After 1.4.1.0" in the application note "How to Extract Data from the Binary File of Siglent oscilloscope", E02A that you've already using.
I have not looked closely, but this document doesn't seem to be perfect, otherwise I would have said you should just treat the SDS800X HD like a SDS2000X HD. In any case, I've already asked for that document to be revised.
I can tell you for sure, that the SDS800X HD has 480 codes per division like the SDS2000X HD, not 25 like the ancient 8-bit SDS1000X.
EDIT: oh, and it might well be that you need to upscale this value to 16 bits: 480 * 2^16 / 2^12 = 480 * 16 = 7680;