Hantek DSO5072P Issues - Page 1
Forum section: electronics / testgear

author: kuez
author_rank: Newbie
timestamp: September 07, 2019, 01:32:21 am
content: I just recently purchased a Hantek DSO5072P and am a beginner hobbyist who knows little about oscilloscopes. However, I have noticed some discrepancies in voltage readings between the two channels, specifically in regard to the 1kHz 5V square wave used for testing the probes and compensating. Channel 1 reads an almost perfect square wave with the correct frequency and voltage while channel 2 reads quite off. This issue has only appeared a day after unboxing the scope and has continued to puzzle me. I believe that the issue is most noticeable in the transition between 500mV/div and 1V/div; there is an audible relay click and the undershoot and overshoot then occur. Although, I cannot see the measurement fully at 500mV/div so I would be unable to answer whether or not there are any discrepancies. I have provided some imaged to provide a visual aid to any potential aides to my issue.

author: Microcheap
author_rank: Frequent Contributor
timestamp: September 07, 2019, 03:07:38 am
content: Have you already done the compensation of your probes?https://www.circuitspecialists.com/blog/oscilloscope-probe-compensation-adjustment/

author: kuez
author_rank: Newbie
timestamp: September 07, 2019, 03:27:16 am
content: Yes, I have. The compensation capacitance for both of the channels worked fine on the first day of use; the square wave had very nice edges. I have tested both probes on channel 1 and they work fine, this issue is only on channel 2 where the waveform is largely out of tune with channel 1's, which, in regard to compensation, I believe the difference is too great to be related. Thank you for your response and let me know if you have any further inquiry into my issue.

author: kuez
author_rank: Newbie
timestamp: September 07, 2019, 03:48:36 am
content: I think it is worth looking at the relationship between volts/div and the displayed signal.

author: tinhead
author_rank: Super Contributor
timestamp: September 07, 2019, 12:07:42 pm
content: Quote from: kuez on September 07, 2019, 01:32:21 amit is broken, you might be able to repair it, but if you have warranty, why bother?

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: September 07, 2019, 12:30:34 pm
content: You have to compensate a probe for a channel, can not go swapping probes across channels. That's why they provide those colored rings, so that you know which probe goes where.

author: Microcheap
author_rank: Frequent Contributor
timestamp: September 07, 2019, 04:05:01 pm
content: As @GeorgeOfTheJungle pointed, you need to match the compensation of each probe to a specific channel, use the color rings to help identify them.Try to connect one probe to CH1, and compensate it adjusting that small trim cap in it. Now attach the other probe to CH2 and do its compensation too. Check if the problems is solved.If not, swap the probes to a different channel and try the compensation again. Check the shape of the waveform on both channels, this way we can determine if the issue is in the probe or the scope.edit: I just noticed that the attenuation of your oscilloscope is set to x1 so I remembered to tell you that you need to change the switch on your probe to x10 position before doing the compensation

author: vk6zgo
author_rank: Super Contributor
timestamp: September 08, 2019, 01:17:22 am
content: Quote from: GeorgeOfTheJungle on September 07, 2019, 12:30:34 pmWell, you can, pretty much, with mostanalog'scopes, as all their inputs look pretty much the same to any external source.The matching may not be "perfect", but it is "near as dammit" the same.As that part of a DSO is purely analog, I see little reason why they would be any different.The coloured rings are so you know which channel to look at when you use the particular probe.