Products > Test Equipment
Siglent - 11/20 - New SDS1104X-U, 4 channel 100MHz, 1Gsa/s economy oscilloscope
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switchabl:

--- Quote from: Fungus on December 06, 2020, 04:59:10 pm ---
--- Quote from: switchabl on December 06, 2020, 03:45:54 pm ---probably zero-padded to 16k?

--- End quote ---

Why would they zero-pad it?

--- End quote ---

I don't know, and I don't think they should (rather than just having 16k actual data points). But it sure looks like it no? If they didn't, you wouldn't see the that much detail on the side-lobes.

It doesn't look like that FFT uses much more than 4k of data in any case. If there is a way to use more, I didn't find it. This is with a current firmware and using "Memory*" as the source (whatever the * means).
EEVblog:
Teardown photos:
https://www.flickr.com/photos/eevblog/albums/72157717234695506

Yep, much simpler front end.
merser:
Definately looks a good alternative to the DS1054Z but for Oz buyers its more like $630 not $399. Price point is similar with the rigol.
TurboTom:
Just for comparison: Here's a shot of both the FFTs of a DS1000Z and a MSO2000A with a signal as per @rf-loop's example (dual-tone sine 300&350kHz). For every of those screenshots, I've optimized the settings to the best results. Actually, I wouldn't call this "utterly useless", especially DS1000Z with the updated firmware (already dating a few years back) made a lot of difference. But still, the new Siglent (and other's as well) scopes' FFT wins hands down, especially usability-wise. The peak search / table function appears to be a very nice add-on, usually only to be found in SAs.

Edit: Added another FFT of the DS1000Z with the same sampling rate as @rf-loop selected on his SDS1000U. Here, the deficiencies of Rigol's FFT implementation get clearly obvious. Calculations point into the direction that Rigol's sampling-memory based FFT processes at least 50kbytes of memory, assuming that each column on the screen represents one bin of resolution at minimum available kHz/div setting.
rf-loop:
@TT
Oh you just take this ultra simple example out from context where only purpose was tell that Siglent do not hide things like FFT data length and also user do not need calculate bin resolution because it is also displayed. It was only purpose about this image, and also show there is markers and peak search etc . This was also not my test at all but from Siglent marketing material where just display that hey there is also peak search.

Also here is markers, now for Delta.  And instead of dual tone here is used "triple tone"



In this image split window display. Carrier is over display range but not worry, of course level is there just right. Only adjusted so for get more noise level to bottom.  1MHz, AM modulate 1kHz 20%. (As can see (as can see sidebands levels are -20dBc.)




Here full window display, 1MHz, AM, 1kHz, 100% (as can see  LSB and USB levels -6dBc.)

It is not SDS1x04X-E what have 8 times better resolution with 1048576 points FFT data length when X-U model have 131072 points what give here with 5MSa/s (5MHz)
5000000Hz/2/(131072/2)= 38.15Hz when  X-E model have in same place  4.77Hz.

As can see in images this signal is very easy to SDS1104X-U. This is resolution for 0 - 2.5MHz band. Of course if take 0 - 500kHz FFT like in @TT image then Siglent X-U  FFT bin is  7.63Hz.

This table can also show more, also freq etc but I turn these off and only show delta with just only 3 markers for more clear visibility.


In this image tiny bit more challenging case but still without any problem with SDS1104X-U.
Signal 325kHz sine, carrier level -40dBm. AM modulation with 100Hz. Modulation depth 0.2% using -40dBm carrier  sides need be -100dBm level (-60dBc).  Just like checkbox - done.

Also it tell that input channel noise level is not very bad. Using full BW in same setup rise base noise level bit. If you think rise this persistence yellow noise top to -110dBm line it is just there. (note averaging)

This is what you can try...

ETA:  Table in Reply #65 corrected. There was error in amount of available memory.
Right is: 1 channel alone on, max 14M. When 2, 3 or 4 channels simultaneously on, all channels have max 7M !
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