Is my hantek DSO2C10 bad/inaccurate?  - Page 1
Forum section: electronics / testgear

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 03:40:31 am
content: New here. Not really knowledgeable on scopes. This is like my 3rd scope.New from amazon. Did the dso2d10 to dso2c15 conversion.The scope reads random mv reading without anything hooked up. I was testing a inline power meter and went down the rabbit hole and saw my scope reads high. My ham radio samlex sec1235m ps reads 14v on one ch and 14.1 on the other. My fluke 16 reads 13.85v ive tested some 1.5v aa batteries and it reads 1.60v on a 1.44v batteryThis cant be normal.Heres a video of what I am seeinghttps://youtu.be/RxbomZHTxQg

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 04:10:15 am
content: Scopes are not multimeters, their accuracy, especially on high V/div setting is not good. You can only do so much with 8-bit ADC.Your full screen vertical display is 5 V/div * 10 div = 50 V. 8-bit ADC can show 256 values. Assuming the screen shows full scale ADC range, one LSB is 50 / 256 ~= 200 mV. You can see your reading jump by that much. This is ADC changing its value by 1 count. This is the best it can do.Scopes are not good at dealing with high voltages. That's (among other things) why there are 10x probes - to bring the input voltage into an acceptable range.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 04:56:03 am
content: Quote from: ataradov on August 31, 2022, 04:10:15 amseems like it should be accurate at 12v stuff. Im not trying to read millivolts. Even probe compinsation reads funny

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 04:59:53 am
content: It is irrelevant what things seem like. I explained the math. It does not matter what the input voltage is, what matters is V/div setting. With your setting the resolution is 200 mV, so the minimal difference it can notice is 200 mV.Use 10x probe and it would be more accurate.

author: pcprogrammer
author_rank: Super Contributor
timestamp: August 31, 2022, 05:28:01 am
content: If you bought a scope with the idea to accurately measure some DC voltage, than you have a wrong perception of what scopes are for.A scope is for visualizing signals. Use your DMM to get an average reading of the DC level and your scope to get some insight in the noise on top of this DC level. So connect a 10x probe, select AC input on the channel and dial the sensitivity to mV/div range. This way you can see how much noise there is on your DC supply output.A fat chance it is way more then 200mV peak peak.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 05:28:25 am
content: Quote from: ataradov on August 31, 2022, 04:59:53 ami believe it has stopped working. I cant get it to read anything 😕

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 05:29:53 am
content: What exactly have you done? You need to provide more information if you want help.

author: pcprogrammer
author_rank: Super Contributor
timestamp: August 31, 2022, 05:36:38 am
content: Treat it like a Windows machine. Turn it off, wait an turn it back on again. See what happens and report back.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 05:38:45 am
content: I will restart it and see.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 05:55:32 am
content: Im uploading a video because its hard to describe whats happening here. Ive been using this oscilloscope for about a week (August 18th) and its not ever acted like this. I unlocked it the 3rd day i had it. I mostly use it to look at the output of my inverters in my solar system. So i hadnt really used it to look at dc. But if i had to do a alignment on a amateur radio im not sure this would be usable lol. Maybe im doing something wrong. Is there a way to restore it to what it was originally from the dso2c15 hack ?

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 06:01:46 am
content: This is weird. I get a sinewave when i put my finger on the probe. A perfect sine.Heres the clip of what its doinghttps://youtu.be/6-E48DbSndc

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 06:04:07 am
content: I doubt any low end scope would be useful for anything radio-related anyway.Again, from what you shown so far your scope does exactly what it should do. Any other reasonably priced scope would behave the same way.

author: pcprogrammer
author_rank: Super Contributor
timestamp: August 31, 2022, 06:04:40 am
content: Yes you can restore it to the original. Check out the threads about the hantek on how to do it.https://www.eevblog.com/forum/testgear/hacking-the-dso2x1x/https://www.eevblog.com/forum/testgear/new-hantek-dso2x1x-models/https://www.eevblog.com/forum/testgear/hantek-dso2x1x-firmware-updates-and-best-use-practices/

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 06:06:09 am
content: The frequency you see is 60 Hz from the mains. This is normal.On the battery measurement you likely see something similar. Change the time scale to fully see the signal.And keep it on DC long enough to actually see something useful, don't just randomly change stuff.Your calibration reads 5V, just like the label on the output says. The probe is overcompensated though.Ah, I see. For the measured voltage it shows RMS value, which is approximately 5 Vpp / 1.41 = 3.55 Vrms. What do you want it to show for AC voltage? Also, it says right on the label "DC RMS".

author: pcprogrammer
author_rank: Super Contributor
timestamp: August 31, 2022, 06:14:12 am
content: Quote from: powerstroke7.3 on August 31, 2022, 06:01:46 amThat is perfectly normal. You are an antenna for the electric field the mains power generates.I watched your video, but could not see how you measure mains. Be aware that measuring mains voltage is very dangerous, and can blow up your scope. Has to do with ground and of course the relatively high voltage of mains. 120V in your case can still provide a deadly blow.You should use either a differential probe or a small transformer to bring the voltage down and provide galvanic separation.Could not spot why the DC voltage is not measured though.Edit: this mainly due to what ataradov also mentioned, the random changing of settings and moving the camera around so much it could cause some epileptic seizure

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 06:42:34 am
content: Had a bad probe. I was using a probe i bought years ago for my old tek.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 06:50:59 am
content: Quote from: ataradov on August 31, 2022, 06:04:07 amare they really this bad? Techcorner and all these you tube guys raved about this scope. I have a old tektronix 2247a but it developed a problem where it only works on .1ms to .5ms sec/division.Am i better off with a older tektronix scope? I can find one locally for about 100-200 usdI cant use this thing for anything much as far as i can tell. I cant see how it could be this bad?Im a amateur extra class . I know a little, not much, i work on radios. But i cant imagine using this other than a toy to get a general feel visually

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 06:58:15 am
content: Quote from: powerstroke7.3 on August 31, 2022, 06:50:59 amThey are not bad. They are just not designed for what you want to do. They are also horrible at hammering nails.Quote from: powerstroke7.3 on August 31, 2022, 06:50:59 amIt is a decent low end scope. But what you want to do is not possible even with higher end scopes, this is not what differentiates them.Quote from: powerstroke7.3 on August 31, 2022, 06:50:59 amIt depends, but most likely no. Why do you think old Tek scope would be better here? Modern digital scopes are better in almost all possible practical respects.Quote from: powerstroke7.3 on August 31, 2022, 06:50:59 amIt is extremely useful for a ton of tasks, but measuring high voltages is not one of them. Scopes in general are not measurement tools, they are for observing waveforms. If this is not what you want to do, then you don't need a scope.There is also a question of experiment setup. For example, why do you need to measure that 12 V? What do you expect to see here?As was described, you may want to measure noise on top of 12 V DC. In this case you can measure DC using a multimeter and use AC coupling to measure the noise. In this case you would need way lower V/div setting, resulting in a much higher accuracy. This is where scope is irreplaceable.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 07:13:17 am
content: Quote from: ataradov on August 31, 2022, 06:58:15 amWhen doing an alignment on certain radios you're mostly going to be looking at very low voltages reference voltages in that type of thing and in some cases they need to be absolutely spot on for something like a local oscillator or PLL Other times I'm looking at frequency. Which this thing does seem to be pretty good at reading. I don't generally bother to look at 12 V unless I'm checking to see if it's there or not. And unless I'm working on older radios I'm not usually dealing with high voltage but occasionally I do work on radios that have 900 V on the plate.I picked it up to look at the wave form coming out of the supposed pure sine wave inverter when i couldn't get my tektronix to work. had to make sure that it was not a modified sine wave. I have another 24 to 120v inverter that is causing 20db over s9 noise in my radios reciever, so ive used it to look at that dirty thing.I have also used scopes in the past to look at the AC ripple in dirty DC power supply. Ive had several older scopes. Some very old. I didn't figure anything older with a crt could possibly compare.So are there ones that will more accurately measure dc and ac voltage from say 1-40v? With precision?

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 07:20:39 am
content: Quote from: powerstroke7.3 on August 31, 2022, 07:13:17 amIf it is mostly DC, then use a multimeter. That's what they are designed for.Quote from: powerstroke7.3 on August 31, 2022, 07:13:17 amUse a scope for that.Quote from: powerstroke7.3 on August 31, 2022, 07:13:17 amMultimeter again.Quote from: powerstroke7.3 on August 31, 2022, 07:13:17 amThis is some serious stuff, you need to have proper probes and adapters in either case.Quote from: powerstroke7.3 on August 31, 2022, 07:13:17 amAnd you can do that. That's exactly what scope is good for. But again, proper high voltage probes are required, otherwise you will kill the scope.Quote from: powerstroke7.3 on August 31, 2022, 07:13:17 amNot really. You can get 12-bit ADC scopes which will have better resolution, but in your case you would still get only 50 mV resolution. And they are WAY more expensive. So much expensive that I personally would not stick 40 V into them without a really extreme need.If you need to do this, your experiment setup is likely incorrect. Scope is not a measurement tool. None of them are.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 07:32:31 am
content: Quote from: ataradov on August 31, 2022, 07:20:39 amyeah ive always used my dvm or a vtvm mostly and frequency counters. Have a hv probe for fluke. 900v dc is no fun. Tends to not feel good. Work with one hand in pocket so it cant cross your heart. Why i avoid working on older radios.I plan to use this to measure ESR of electrolytic capacitors. Should be interesting. But no i didn't plan to use it for measuring voltage. Im used to older scopes that you really have to count lines to guess what the approximate voltage is. My friend claims his FNRSI tablet scope is dead accurate for voltage readings so i thought hmmm. The bad probe really threw me off. But i do think this firmware is less accurate than what it shipped with so maybe ill roll it back. I really wanted the signal generator after i realized these main boards were all the same.I appreciate your time and help.

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 07:37:09 am
content: Quote from: powerstroke7.3 on August 31, 2022, 07:32:31 amIt is still the best approach with digital scopes too. It is not that hard and you can "guess" much more accurately than the measuring thing because humans are way better at ignoring noise that does not matter in a specific case. It is helpful to have individual measurements on the screen, but not that multimeter mode. This mode is a gimmick of low end scopes. It is like a transistor measurement mode on a multimeter.Quote from: powerstroke7.3 on August 31, 2022, 07:32:31 amLOL, no. FNRSI are trash. They may seem more accurate because they do a lot of "creative" averaging and other trickery. They are not real tools.

author: pcprogrammer
author_rank: Super Contributor
timestamp: August 31, 2022, 08:12:57 am
content: Quote from: powerstroke7.3 on August 31, 2022, 07:32:31 amTo do this there are also dedicated instruments that do a better and quicker job. Even the cheap ones.As ataradov stated a scope is to make signals visible. They are also reasonably good for determining frequency, but accurate voltage levels not so much.Quote from: ataradov on August 31, 2022, 07:20:39 amThe math shows 10mV if the scope is set to 40V full screen (if this is possible with the volts per div setting of course) 40/4096 = 0,009765625. (8 divisions and 5V/div)But that is nitpicking and I agree that such a scope is very expensive and I would also be very careful with inputting a higher voltage directly into that scope. Don't want to blow up a $10K or plus scope.About the FNIRSI scopes, I wrote this in the Hantek thread too, ataradov is right. They are way bad compared to the Hantek and only show seemingly correct readings due to a lot of software filtering done on the data. And I know this because I reversed engineered the damn thing. Made the schematics for both of the FNIRSI ones and the Hantek, so can also state that the hardware of the FNIRSI is crap compared to the Hantek.The Hantek is reasonable, but also has a lot of software issues, and maybe even some programmable hardware issues. (Within the FPGA used in it)

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 08:21:15 am
content: Quote from: pcprogrammer on August 31, 2022, 08:12:57 amwhats the best firmware/ software for my hantek? Some say theres better ones for accuracy

author: ataradov
author_rank: Super Contributor
timestamp: August 31, 2022, 08:32:33 am
content: You are running into physics limitation. There is no firmware that can solve this. This is like asking what TV can show clear 4K video using VHS tape as a source. The best you can do is average and blur stuff, this is what FNRSI is doing. But this is not adding information. The information was lost after analog to digital conversion happened.But I don't think there is any firmware other than the official one anyway.

author: pcprogrammer
author_rank: Super Contributor
timestamp: August 31, 2022, 08:35:16 am
content: The best I don't know, for what I read about it in the Hantek threads the FPGA firmware 3202. Best to check out the last entries in the threads I pointed to a couple of posts back.Or somewhere near this posthttps://www.eevblog.com/forum/testgear/new-hantek-dso2x1x-models/msg4253533/#msg4253533That thread is also the one for asking questions about the software updates and procedures. One of the more involved members can provide a better answer. I never updated mineMore or less just bought it to play with the hardware.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 08:38:48 am
content: Quote from: ataradov on August 31, 2022, 08:32:33 ami had a different one prior to the hack. It behaved differently. But i guess its not going to change much. Theres a few glitches im sure.Can you believe people used to steal vcr to sell for drugs lol 😆 im getting old

author: pcprogrammer
author_rank: Super Contributor
timestamp: August 31, 2022, 08:43:32 am
content: Quote from: ataradov on August 31, 2022, 08:32:33 amYes, and what did they do in the FNIRSI, when the signal goes beyond ~44MHz, they just calculate a sine wave to display. The only characteristics of the original signal taken into account are the frequency they determine and the amplitude, and the latter not even correctly, because sweeping from 43MHz to 45MHz shows an increase in amplitude on the switch pointSee my video on thishttps://youtu.be/SApQPL3pDvc(Around a minute into it)Quote from: ataradov on August 31, 2022, 08:32:33 amFor the Hantek you are right, but for the FNIRSI there is the one I wrote.

author: powerstroke7.3
author_rank: Contributor
timestamp: August 31, 2022, 08:44:41 am
content: Quote from: pcprogrammer on August 31, 2022, 08:35:16 amok. I dont usually mess with software or firmware. Not my stong suit. I barely figured out the hack