Lower peak of wave form much thicker than the upper one in Rigol DS1104Z Plus - Page 1
Forum section: electronics / testgear

author: 7AudioBB
author_rank: Contributor
timestamp: March 17, 2024, 03:02:36 am
content: Can someone tell me why the bottom part of this square wave much thicker than the top? I'm using the built in 1kHz square wave source with a probe set to 10x. The wave is captured with the 'Auto' button. In YouTube other people don't seem to have this issue with the same type of oscilloscope when 'Auto' is pressed. For some reason at a lower position all waves have a thicker line at the bottom. If I move the position to 0Volts, it looks normal. Why is this happening? Is it normal, or my (new) Oscilloscope has a problem? Please see the screenshot below:

author: RoGeorge
author_rank: Super Contributor
timestamp: March 17, 2024, 06:36:06 am
content: Quote from: 7AudioBB on March 17, 2024, 03:02:36 amNot normal. Try a self calibration, then test again. If that doesn't fix it, return the oscilloscope and ask for a replacement or for a refund.To run the self calibration, unplug all the probes from the front panel of the oscilloscope, leave the oscilloscope running like that for half an our (to get to thermal equilibrium), then press Utility -> Down arrow -> Self-Cal -> Start in order to start the self calibration. Let it finish the procedure, it will take about 10-15 minutes or so, don't interact with the oscilloscope during self-calibration.After it finishes (it will write a calibration complete message at the end), turn the oscilloscope off (from the power button), and on again. Plug the probes, and check the square wave signal again.

author: Aldo22
author_rank: Super Contributor
timestamp: March 17, 2024, 10:05:31 am
content: Is this also the case on other channels?Quote from: 7AudioBB on March 17, 2024, 03:02:36 amYou mean when you move the 0V position to the vertical center of the graticule? Because 0V is where the yellow arrow (on the left) is.To be on the safe side, you could also reset the settings (I don't have a Rigol, I'm just guessing).Function Inspection1. Press Storage -> Default to restore the oscilloscope to its default configuration.

author: Anthocyanina
author_rank: Frequent Contributor
timestamp: March 17, 2024, 11:11:44 am
content: this happened before to another person. try getting a replacement. that's defective behaviour.here's a link to the other person's threadhttps://www.eevblog.com/forum/testgear/my-rigol-ds1054z-has-noise-and-beam-thickness-dependency-of-the-vertical-offset/

author: Njk
author_rank: Frequent Contributor
timestamp: March 17, 2024, 11:12:13 am
content: Quote from: 7AudioBB on March 17, 2024, 03:02:36 amSeems you're not alonehttps://www.eevblog.com/forum/testgear/my-rigol-ds1054z-has-noise-and-beam-thickness-dependency-of-the-vertical-offset/msg4805633/#msg4805633

author: 7AudioBB
author_rank: Contributor
timestamp: March 17, 2024, 02:03:31 pm
content: Okay, I've got some news. Thanks for all your comments!I reset everything to default, then did the calibration and the restart, but the issue was still there and the same. With all probes in all channels and with the same probe in all channels too. Then I kept checking the menu and it turns out that when my Acquisition setting is set to 'Normal' I have that thick bottom part. But when I set it to 'High Res', it becomes nice and thin all around, regardless of position. Could this be due to the sample rate? Does this mean my scope is working fine? (Wondering what you set your Acquisition to in your oscilloscope?) Please see images below with 'Normal' vs 'High Res' mode:

author: 7AudioBB
author_rank: Contributor
timestamp: March 17, 2024, 02:16:08 pm
content: I've just noticed that when I reduce Memory Depth to 120K in normal mode, the lines become equal as well. (see image).

author: bdunham7
author_rank: Super Contributor
timestamp: March 17, 2024, 02:21:45 pm
content: Quote from: 7AudioBB on March 17, 2024, 02:03:31 pmIf you were trying to repair it, those observations would be helpful in tracking down what is actually wrong with it. However, it does not change the fact that your new oscilloscope is broken.

author: Fungus
author_rank: Super Contributor
timestamp: March 17, 2024, 02:23:20 pm
content: IIRC this is normal on the calibration signal.

author: Aldo22
author_rank: Super Contributor
timestamp: March 17, 2024, 02:44:48 pm
content: Quote from: Fungus on March 17, 2024, 02:23:20 pmWhy should it?It seems to be a known issue:https://www.eevblog.com/forum/testgear/my-rigol-ds1054z-has-noise-and-beam-thickness-dependency-of-the-vertical-offset/msg4808549/#msg4808549

author: 7AudioBB
author_rank: Contributor
timestamp: March 17, 2024, 02:47:39 pm
content: Quote from: Fungus on March 17, 2024, 02:23:20 pmIt happens to any signal from a function generator as well. Also when the probe is not connected and just moving the vertical position, the line gets much thicker close to the bottom of the grid.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 17, 2024, 02:59:33 pm
content: Quote from: 7AudioBB on March 17, 2024, 02:03:31 pmIt's a defective oscilloscope, you should return it to the seller.

author: 7AudioBB
author_rank: Contributor
timestamp: March 17, 2024, 04:45:00 pm
content: Thanks everyone, I've started a return. I'm not sure I'm gonna get the same type again or even the same brand due to this disappointment. What I also didn't like is the very poor quality rotary encoders. You can't feel them click and they easily jump more than needed or skip one turn. You need to press them in hard as well to select items. Display resolution could be better too.In case you can recommend abetter qualityone (with 4 channels and FFT ), please comment here. I'd appreciate it.

author: 2N3055
author_rank: Super Contributor
timestamp: March 17, 2024, 05:27:46 pm
content: Quote from: 7AudioBB on March 17, 2024, 04:45:00 pmlTake a look at Siglent SDS800

author: dobsonr741
author_rank: Frequent Contributor
timestamp: March 17, 2024, 07:16:52 pm
content: Wow, I would not expect it from Rigol. Are these sellers authorized distributors of Rigol, or perhaps EBay or alike, where factory reject might show up?

author: 7AudioBB
author_rank: Contributor
timestamp: March 17, 2024, 08:22:22 pm
content: Quote from: dobsonr741 on March 17, 2024, 07:16:52 pmI bought it from Amazon as brand new. It arrived in the Rigol packaging. It wasn't even in an Amazon box like it supposed to and like others received it in YouTube videos. Not sure what happened but after all I'm not a big fan of Rigol 'quality'.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: March 17, 2024, 08:44:34 pm
content: Amazon is just a fulfillment center for anyone want to sell. What does Rigol warranty status say, about your serial number, I’m curious:https://eu.rigol.com/eu/services/services/warranty-period

author: 7AudioBB
author_rank: Contributor
timestamp: March 17, 2024, 09:26:43 pm
content: Quote from: dobsonr741 on March 17, 2024, 08:44:34 pmWhen I submit the serial number, I get a pop-up message saying: "Please enter a correct serial number".

author: Njk
author_rank: Frequent Contributor
timestamp: March 18, 2024, 08:14:56 am
content: I bought mine on ali. After two years in service, it suddenly refused to boot. I asked the seller about what to do. He gave me a contact to the local Rigol FAE. I'd e-mailed to the FAE and it was agreed that I'll send the broken scope for free repair. It took a considerable time for them to fix it because they'd to order the replacement part from China but finally I'd received the working scope back. Perhaps it'll make sense for you to find and contact the Rigol reps in your region.

author: 7AudioBB
author_rank: Contributor
timestamp: March 18, 2024, 01:13:19 pm
content: Quote from: Njk on March 18, 2024, 08:14:56 amI see. I've returned mine already. Probably gonna go for a Siglent next.

author: Anthocyanina
author_rank: Frequent Contributor
timestamp: March 19, 2024, 04:12:34 am
content: Quote from: 7AudioBB on March 18, 2024, 01:13:19 pmthe new siglent 800x HD series looks like it will become the new ~400$ standard. have you looked at those? they have a 12bit vertical resolution. rigol also released 12 bit scopes in that price range, and they seem to work fine, but they are just horribly ugly

author: 7AudioBB
author_rank: Contributor
timestamp: March 19, 2024, 02:43:35 pm
content: Quote from: Anthocyanina on March 19, 2024, 04:12:34 amYes, these seem to be great, especially the SDS824X HD. Although as they are new, they don't have many reviews yet to see how they perform over some time of regular usage.

author: 2N3055
author_rank: Super Contributor
timestamp: March 19, 2024, 03:07:31 pm
content: Quote from: 7AudioBB on March 19, 2024, 02:43:35 pmWhat do you mean?There is 20 times more material about details how it performs than Rigols that have been out for more than a year..Performa01 wrote a veritable 100+ pages book about it:https://www.eevblog.com/forum/testgear/sds800x-hd-review-demonstration-thread/msg5293741/#msg5293741You don't see bug reports because there is pretty much no bugs to mention .

author: ebastler
author_rank: Super Contributor
timestamp: March 19, 2024, 04:22:24 pm
content: Quote from: 7AudioBB on March 19, 2024, 02:43:35 pmAnd, like the DS1054Z, they are easily "upgraded" by the user, via unlock codes generated by a Python script. So you could buy the 804 or 814 model and upgrade it to 200 MHz bandwidth and 100 MPts memory later.Each model does come with four probes which are only specified at the respective scope's bandwidth, but you may not need all four probes to be 200 MHz. (Even if you do, with the relatively large price step from the 814 to 824 you would be better off buying additional probes separately. And you could buy niver probes than the Siglents, which are ok but don't handle that well.)

author: 7AudioBB
author_rank: Contributor
timestamp: March 19, 2024, 07:21:42 pm
content: Alright, thanks for the info. Didn't know they've been reviewed so much, also that you can just 'hack' them.