Author Topic: Siglent SDG1020 square signal "dirty"  (Read 14740 times)

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Offline Wuerstchenhund

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Re: Siglent SDG1020 square signal "dirty"
« Reply #50 on: April 29, 2013, 09:26:36 am »
This oscillation problem is solved by Siglent:

(due to Holiday in China, there is now open question how they support these who have this problem. If you have this problem, please contact your Siglent distributor / seller for get after sales customer care.)

Unfortunately that doesn't work for me as my seller is of no help. But then since I added the SMD capacitor the main issue (excessive square wave jitter) seems to be gone now.

After opening up my unit I found that the general hardware design looked perfectly fine but that there was some sloppyness during assembly which lead to the PSU cable being damaged (insulation cut off by sharp corner with wires exposed) as it was stuck between parts of the housing. Oh well, at least it didn't cause any damage and was easily fixable.

Since you sell this stuff for a living, have you seen any SDG5000 yet? Spec-wise it looks very interesting (aside from the missing LAN port) but I wonder how it performs in the real world.
 

Offline rf-loop

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Re: Siglent SDG1020 square signal "dirty"
« Reply #51 on: April 29, 2013, 09:56:35 am »
This oscillation problem is solved by Siglent:

(due to Holiday in China, there is now open question how they support these who have this problem. If you have this problem, please contact your Siglent distributor / seller for get after sales customer care.)

Unfortunately that doesn't work for me as my seller is of no help. But then since I added the SMD capacitor the main issue (excessive square wave jitter) seems to be gone now.

After opening up my unit I found that the general hardware design looked perfectly fine but that there was some sloppyness during assembly which lead to the PSU cable being damaged (insulation cut off by sharp corner with wires exposed) as it was stuck between parts of the housing. Oh well, at least it didn't cause any damage and was easily fixable.

Since you sell this stuff for a living, have you seen any SDG5000 yet? Spec-wise it looks very interesting (aside from the missing LAN port) but I wonder how it performs in the real world.

I have not seen any SDG5000 yet.
Under tests now.


Last time I order lot from Siglent I think if I get one for tests but somehow I have learned that what ever machine is I littlebit afraid first versions.
If it is washing machine, if it is car, if it is TV, etc.
Mostly they are not mature when they first come on market. Least it is good to short time look around what kind of comments are available.
Of course this may lead wrong also becouse if there is some problems... and related to this some negative opinions and then lot of peoples do not buy also later versions becouse there is now "bad opinions" over this brand. If later come more mature version... peoples still keep they first opinions and everywhere can read these and then every corner they talk that this name/model  is bad and now also these other peoples who never have made any tests repeat also these bad opinions what they have heard perhaps time ago.
« Last Edit: June 04, 2013, 02:23:14 pm by rf-loop »
If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
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Offline rf-loop

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Re: Siglent SDG1020 square signal "dirty"
« Reply #52 on: June 22, 2013, 04:06:03 pm »
Original message from wrong thread (SDG5000 series test thread is wrong place)
Hi,
Did you see this review ?

interesting moments:  49:30 ,  54:45 and 57:30 - what happen ?

I know, SDG1020 is low budget waveform generator, but it is still Siglent (maybe I'm wrong)
I may have difficulty understanding some sentences, but the waveforms look very strange.




Yes, this is well known and many times here and there handled and also circuits analyzed some amount. Also there have been improvement for this glitch issue.



https://www.eevblog.com/forum/testgear/siglent-sdg1020-arbitrary-fungen-first-impressions-and-a-possible-signal-glitch/msg185396/#msg185396


and here many things: http://siglent.freeforums.org/sdg1000-arbitrary-multifunction-generators-f13.html   

(also some wink for modify)



But other things like square wave glitch have handled lot of and littlebit more.
Then 54.45.  Sampling frequency is 125MSa/s. It reads also in specifications.
125MSa/s period is just 8ns.
This kind of equipment circuit principle need do it. (it depends frequency(period) and pulse width.
More advanced (and typically more expensive) equipments have some methods for avoid this.
Square wave is then special case becouse it is derived from internal sinewave using cheap simple comparator solution. For low frequencies, better square can do using pulse function.

57.30 and after then this "gameboy" playing - for what kind of purpose.  Perhaps nothing useful to do - perhaps if this, then coffee break is perhaps better use for time. ;)
Of course sometimes this kind of playing can do ecample for finding bugs what leads to system crash.


Please continue this discussing here. Not about this case in SDG5000 test thread, please.

« Last Edit: June 22, 2013, 05:34:06 pm by rf-loop »
If practice and theory is not equal it tells that used application of theory is wrong or the theory itself is wrong.
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Harmony OS
 

Offline Siglent

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Re: Siglent SDG1020 square signal "dirty"
« Reply #53 on: June 26, 2013, 02:23:34 am »
Is this the same thing you guys are talking about? 

I have an SDG1025 and was going to send it back under warranty for a replacement, but if they are all like that then maybe I'll have to live with it.

Attached are scope snapshots.  Yellow are channel 1, 1khz square wave and blue is channel 2, 1khz square wave.  I set it on infinite persistance for a few seconds to show the glitches.

Channel 2 is fine, as is channel 1 pulsed output(not shown), it's just channel 1 square wave that looks like crap.

Steve

The question is due to changes the circuit, in the new version has been resolved (increasing the capacitance), it will be updated in the latter.


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