TWT #27: DSO138 How to Use Basics

Today we'll go over the basic functionality and features of the DSO138. On a previous video sekdude2 asked if I could go a basic, how to use tutorial on the DSO138. I finally put one together, hopefully it helps!

[@wendellhammond7853]

Thank you very much you answered all my questions all in one short video after watching 20 plus videos and not learning anything I didn't already know . the instructions with mine simply told how to calibrate the prob .

[@apached343]

I am less than half way through, and have already learnt vital information on operating the DSO 138! My display was all over the place, and its great to now know how to revert to factory default. Thanks.

[@TinkeringWithTerrius]

Glad it helped!

[@whitefields5595]

Thanks for taking the time to do this for us all. I bought this based on videos like this. Most of my hobby work is relatively low bandwidth so this scope is ideal. Your video is short, accurate and concise with no waffle or 'opinions'.

[@TinkeringWithTerrius]

My goal was to create a simple how to use guide, I did my best to edit out any opinions or waffles that weren't relevant. I'm glad to hear you found it helpful and that my goal was achieved! Thank you for taking the time to comment!

[@otiebrown9999]

Excellent. This is the first accurrate demonstration of how to use the 138. Thanks!

[@TinkeringWithTerrius]

Thank you for the comment! I made this video because a commenter asked for it, I was actually surprised that more people hadn't done a simple quick overview of it like this.

[@stephencooper5800]

I had so many questions after building one of these and this answered every one of them. Even the ones i had no idea how to articulate, such as performing the reset when on the vertical selector. Thanks

[@TinkeringWithTerrius]

I'm glad the video was helpful!

[@Eurus721]

Just got one and that really saved me time and confusion. Well done video too. Thanks

[@TinkeringWithTerrius]

I'm glad the video was helpful! When I had finally assembled it I certainly spent quite a while trying to figure out exactly how it worked. The manual is helpful, but I figured having a video explanation might be beneficial for anyone that wanted something more visual.

[@justinholtkamp9972]

Very helpful knowing the multiple button tricks!

[@randyguay7115]

Very helpful i got one to tinker with and of course thee instructions left a bit to be desired. And now i am off to look and learn more.

[@andrebalsa203]

Very good video, thanks for sharing. Very clear and detailed explanation of how this ultra-cheap DSO138 works.

[@TinkeringWithTerrius]

I'm glad the video was helpful! It still surprises me that this video is relevant so many years later!

[@ronplucksstrings7112]

Clearly and well presented. Thanks!

[@kitecraft]

Very helpful video. Thank you for taking the time and effort to make and share it.

[@TinkeringWithTerrius]

I'm very glad to hear that it was helpful. Thank you for commenting!

[@mikegleasonjr]

Thanks, playing with mine while listening to your video helps!

[@TinkeringWithTerrius]

Glad to know it helped!

[@blackbox330]

Sir, Excellent video.

[@Dontdoxme9268]

Thank you thank you thank you! As a hobbyist I can't justify a $400 oscilloscope. And this will be my first one to play with.I know and bought this knowing it's not much better than a toy. But that's exactly why I want it. To toy around with. So a basic tutorial video will be very helpful! Thanks to whomever suggested you make this video as well.

[@TinkeringWithTerrius]

Well I hope you find/found the video helpful! That's the same situation I was in, I really wanted to play with an oscilloscope but there were none reasonably priced on ebay here, and this was on sale on Amazon (I bought the un-assembled one, it was very good practice for soldering). It has it's quirks but it is a very handy piece of equipment and the skills learned from it can be transferred directly to a proper DSO if it ever becomes available!

[@merlingt1]

Strongly disagree. If you don't want to get discouraged as a new hobbist DON'T buy Chinese crap equipment like this. My calibration C4 barely works and C6 does nothing.

[@dogdogdogdogdog2546]

These oscilloscopes are more used to get a rough idea of what is going on. I am not a pro at electronics but when I create oscillators; sometimes I want to know the output without using a LED or some sort of Ardunio. The DSO138 is trash compared to Rigol series. But the DSO138 was not meant to replace Rigol, it's targetting to the hobbyiest audience I believe.

[@whitesands928]

Thanks, helped me a lot.

[@brightidea1]

Thanks very much for the video. I notice you are using this with no case, and others have commented that their unit stopped working after a short time. I suspect it may be latent ESD damage caused by using the scope with no case.

[@TinkeringWithTerrius]

Thank you for the comment! That's a really good observation. I hadn't really considered ESD damage, but that would make sense in some of the issues people have had with it.

[@alico797]

Helpful and interesting, both... Thanks!

[@TinkeringWithTerrius]

Thank you for the comment, I'm glad to hear this video is still helpful!

[@Ultraread]

Thanks a lot for this

[@rongarza9488]

The DSO138 oscilloscope arrived yesterday (as did the tablet holder, but that's not related to this). Wow! This little item is quite the window into a circuit. I used the DC005 plug (see specs online) with a 9 volt DC adapter with a positive tip. The acrylic case is not really a good idea. So now I can see what my projects are doing, one trace at a time of course.

[@TinkeringWithTerrius]

Glad to hear it arrived and you're enjoying it so far! It is certainly super helpful for visualizing what a circuit is doing! Despite it's low bandwidth I think for the price it is something every electronics hobbyist should have. I just wish the screen was a bit bigger! Almost makes me tempted to buy some of the other JYE-Tech scopes to see how they compare to it, but they are more expensive than the DSO138.

[@stooory]

Thanks for the video very helpfull

[@TinkeringWithTerrius]

Glad you found it helpful. Thank you for taking the time to comment!

[@stooory]

Tinkering With Terrius thanks for replying . Though i have a problem with my dso138 it's too noisy not sure why .

[@trainliker100]

The DSO138 (and the smaller DSO128 "Mini") has an easy to fix issue where the waveform can look a little bad with high input signals. Voltage divider R6, R7, R8 are a bit too low and put a little too much load on the output of U2B. All you have to do is increase them by ten times (use 1% resistors). This works fine because the voltage divider feeds the high impedance non-inverting input of U2C.

[@SteveRobinett]

Excellent overview! I'm waiting on my kit and will find this invaluable (assuming I assemble it correctly!)

[@MrWhaatay]

I bought the upgraded DSO138 mini which runs off 5 volts so you can use any USB power supply or battery pack. Cost me a little over $11 including the case. Put it together and it works great.

[@SteveRobinett]

The kit arrived, I assembled it and it works great. This video was so very helpful. Thanks for making it!

[@vernoncarter5285]

Thanks very much. Just bought one or should I say just received it long long way from China Does what it says on the box

[@mjyanimations1062]

Can anyone help me? I had ny dso for several months and it worked fine. but now while measuring the inbuilt test square wave, whenever I try to center the trigger with the graph or adjust the trigger in any way, the entire graph moves up or down by a few volts.I have to center the waveform with y=0v every time. this didn't happen before and is really annoying.

[@generaza7609]

Does anyone know if there is a way to re-engineer this DSO to sample at a lower rate, such as 1 sample per second or minute? If someone new how to do this, it would make a great solar power sampler for custom solar setups. I have checked the suppliers and they all state it can sample at a max of 1 mega samples per second. They do not tell you how to change this. The docs say nothing regarding that or the USB connector.

[@seniorblackfox7001]

Excellent review, Thanks. My current or starting interest in this oscilloscope is to determine how much ripple or noise is present in voltage regulators used in RC video models. It seems I have constant noise issues that are hard to trace down and trying to determine what LC filters work best. Will this be helpful in showing/identifying the noise source? Voltages are generally reduced from 12 to around 5vdc. Thanks

[@TinkeringWithTerrius]

It will mostly depend on the frequency of the ripple, though the scope can read up to 200 kHz so I think you should be good. The scope itself can have a small amount of noise, but it should be easy enough to see the difference between its noise and the measurement noise. At 5vdc you should be able to get quite high resolution measurements.

[@seniorblackfox7001]

Thanks and looks like this should work for my needs. BTY... this is the first of your videos I have run across and you do an outstanding and easy to understand presentation. I will be looking forward to viewing more.

[@brettschacher8644]

I watched a video posted by another guy that shows how to reduce the noise within these scopes by changing a few capacitor connections. I have not gotten my scope working yet and until I get everything finished, like managing to get the BNC connector securely anchored down and the connection to the USB cleaned up satisfactorily. It's a moding video at part 3. I don't know what components are being used in your Vregs so I can't advise aside from using some capacitors of different values on output side of the Regulator. There are diagrams online that show how this should be done. Possibly some value of choke ( Ferrite Beads ) can be used along with the capacitors as a filter. Switching regulators obviously will induce some noise into the circuit which may be obnoxious to your RC communications. I don't think a linear Reg would be as noisy. However, noise may be getting into the circuit from the motors. With all this circuitry so close in the RC unit, RF noise could likely be what you need to address. Simply placing a cap across the connections for power to the motors could help. I would consider using an electrolytic around 220 uf and maybe a 22uf and a 2.2 with a .22 all wired in parallel. Starting with the higher value closest to the battery progressing down in value to the motor. If the motors are brush type the arcing at the brushes is going to be a major source of noise and about the only way to get rid of it beyond the capacitors would be to shield the motor with a faraday cage grounded to the power supply. Shielded cables around anything that carries higher power too at least on the positive leads. Think about how the ignition wires on Corvettes are all or should be shielded to eliminate noise in the radio since there is little or no metal around the engine in a fiberglass car, and how a lot of military vehicles used shielded ignition cables to block out RF noise so they couldn't be detected in combat zones.

[@cw4608]

Thank you this info was excellent. If my PW and Duty are bouncing - Duty between 48 and 52 does that mean I need to do a better job calibrating my probe?

[@TinkeringWithTerrius]

I'm glad the information was helpful! If your duty cycle is bouncing around like that, and you are using the built in test point for the signal, it is indeed possible that your probe needs calibration. Alternately it could be an issue with the signal generator itself. I found in general that I didn't rely on the duty or time readouts of the overlay. When probing actual circuits it wasn't entirely reliable, but it did come in handy as a quick way of estimating the duty cycle or period of a signal.

[@joestubbs3138]

Good presentation - helps greatly with knob pressing - Q.. will it run of a 3 cell lipo 12.6Volts...joe

[@TinkeringWithTerrius]

12.6 might be a tad high, the specified battery voltage is 9 Volts, but it can accept anywhere between 8 and 12 (according to the manual).

[@joestubbs3138]

gotcha and thanks...joe

[@TPsynth]

How would you go about adapting this to 3.5 mm input? Are there female 3.5 to BNC adapters?

[@avinashmaurya8381]

Can I measure home supply voltage or higher?

[@frankkirschner]

Thanks for the video. Very helpful. On my device, the two solder connections that are looped together in your photo and provide the square wave, are not connected to anything. I bought mine assembled. Is there a connection missing?

[@TinkeringWithTerrius]

Glad the video was helpful. The assembler may have decided not to add the calibration loop, as they may have pre-calibrated the unit. If the holes are there and just missing the wire, you could potentially just add it yourself. Or, it's possible that the newer revisions of the DSO138 no longer have this as a feature. I'm not sure how many revisions there have been since I made this video all those years ago!

[@stuffandthings7146]

Do you know whether there is a way to take data off of this device by plugging it into your computer?

[@francoisBonin-phils]

Mine does not sweep anymore...less than one month

[@caraplusmahesh]

Sir please reply me Can I Maximum signals dc volt ....

[@wigdoa8986]

I have the same oscilloscope and i have an issue where it constantly displays a voltage even when the nodes aren't attached to anything. Does anybody know how to fix that?

[@MrRefractions]

Hi, Would this scope be any good for fault finding/building guitar pedals?

[@TinkeringWithTerrius]

I personally don't have any experience with building guitar pedals, so I can't give a definitive answer. I would assume as long as the 200khz bandwidth is high enough, then yes it should work. Be aware however it is a very basic scope and doesn't include any spectrum analyser functionality or waveform generation, though again I am unsure if this would be an deal breaker with building/troubleshooting guitar pedals. I really wish I could have been more help, sorry!

[@olisesundaynduka3689]

Master , l appreciate all your lectures on DSO Scope because l have it. Butpls Master, teach me more on how to use it on things like ... checking the oscillating/ driving signals in smps pwm ICs , Smart TVs scallar boards, TCON board or video signals.... urgently needed Master 🙏. I have no attenuator. Can l add higher value Meg resistor, like 5 to 10 Meg to the testing probe? to steady the triggering amplitude ???

[@rongarza9488]

@Tinkering With Terrius thank you. You could probably make some money by placing ads for trusted DSO138 vendors. The one I ordered from eBay's cinnamon 1956-5 turned out to be just the plastic case, not the oscilloscope. So I'm still looking and don't want to waste any more time.

[@TinkeringWithTerrius]

Argh, I hate when an ebay listing turns out like that. I bought mine through Amazon from the JYE Tech store, but I know that isn't an option in a lot of places. I suppose you could always try banggood I've seen it listed on there, I think they even have the new DSO138 Mini. The mini is their new version that is supposed to have some nice improvements.

[@rongarza9488]

@@TinkeringWithTerrius Thanks for the info. I am happy to report that cinnamon 1956-5 has issued me a full refund. For that I have given a 5-star rating and ordered the oscilloscope from cinnamon 1956-5 again -- this time at more than twice the price of the case (the webpage has been updated to show both the case and the oscilloscope. It does not say it is the Mini version though. I'm also waiting for a tablet holder from banggood. These are great deals but the wait is a test of patience.

[@avinashmaurya8381]

How can I use this as two channels?

[@harrisryder1244]

The time divison (0.1ms) is that representative of each square?

[@TinkeringWithTerrius]

Thank you for commenting! Yes, time is measured on the X axis so the width of each square is equal to the timebase (in this case 0.1ms). The Y axis is the voltage, so the vertical height of each square is representative of whatever precision you are set to for voltage (in the case of this video 0.5v). The green numerical value in the bottom middle of the screen will be how wide the squares are, and the yellow value on the bottom left will be how tall they are. Hope this helps, sorry I didn't reply sooner!

[@kirkguille]

Nice video, can i use the Dso 138 to measure a transient of 50ms on single shot mode? Thanks! :)

[@TinkeringWithTerrius]

I haven't personally tried but based on the specifications of the DSO138, it should be able to handle that.

[@kirkguille]

Thank you ! :)

[@James_Bowie]

Thanks for this. Is this stuff actually documented somewhere in a PDF?

[@TinkeringWithTerrius]

Yes, I believe you can find all of this information in the DSO138 User Manual PDF on the JYEtech website!

[@tablesawer]

Can you tell me what the power supply you used ( converter board ) to plug into the scope?

[@TinkeringWithTerrius]

It is the JYE140 Step-up DC/DC Converter.

[@alexandrevaliquette1941]

IS THERE ANY HACKER DOWN THERE??? The real questions is: "What are the limiting factor?" How can we improve the quality of theses ultracheap O's? -Getting a better probe? -Install metal shielding around some components? -Replacing the capacitor (or any cheap component) with something else? -Get a 9V battery instead of a cheap 9V wall transfo (like I do to save on battery cost)? I'm not an electronic guru, I only have some basic knowledge and KZbin as a perpetual teacher. Alex from Montréal

[@josearmz10789]

Good video just a question, my dso didn't come with the bridge as yours did to calibrate it it is very difficult for me to do so now. Will using a 1khz test tone at 0db in my car work to calibrate it assuming the output voltage is 3.3V. Or how else would I be able to calibrate this sucker. Thanks in advance.

[@TinkeringWithTerrius]

Thank you for the question! Any test tone should work as far as I can tell. I'm unsure if there is a specific reason for the frequency of the supplied test signal or not. The bridge on mine is simply one of the leads I trimmed off after soldering all of the parts. You could easily add one to your unit by soldering on a small length of bare solid core wire if you were so inclined. Unless of course yours doesn't have the holes for the test loop. Hope that helps!

[@josearmz10789]

thanks for the fast response. this is the thing I ordered mine preassembled and I have no soldering iron and no soldering skills. I managed to calibrate it, but since I'm using it to set the gains on an amp somehow the sinewave looks very fuzzy. I know clipping should make the sine wave square at the top but mine starts out smooth and then gets fuzzy. I don't know if the DSO138 I received is defective or how to fix it any help would be appreciated.

[@TinkeringWithTerrius]

That does sound odd, I did experience something like that when I sent it a signal higher than the DSO's 200khz bandwidth could handle, but I assume you are working with audio level frequencies

[@angelcorleone2083]

Thanks again. I am working with car audio but the frequency is 40hz for bass and I'm sure that is not the issue. Since I'm getting the signal from the amp itself instead of the speaker wires that might affect the sine wave. I've ordered another oscilloscope to see if the one I currently have is the issue. Thanks again.

[@josearmz10789]

Ok I'm back again, btw the other account is also mine but was on my phone when I replied. Anyways got a new oscilloscope and the sine wave does not square at the top. it turns sideways as if slanted similar to how it appears on the dso138 just without the fuzziness. Best way to describe it is as if looking at a mountain. Any idea why this happens.

[@paula805]

Can someone please tell me what the other (black) probe is connected to when the red probe is connected to the calibration waveform?

[@TinkeringWithTerrius]

As per the instructions the black (ground) is left disconnected while using the test signal. You simply hook up the red lead and then adjust the variable capacitors to reduce the over/undershoot of the signal.

[@edoardofacciotto7261]

How can I use it with a synthesizer's audio out (3,5 mm) ?

[@TinkeringWithTerrius]

You could use a short 3.5mm male to male audio cable and either remove one end and connect to the bare wires, or simply clip the DSO138's probes onto the appropriate spots of the 3.5mm male plug. However you will only be able to test either the Left or Right channel at at time, not both, if the output is stereo. On a standard stereo 3.5mm plug you will have, Ground (the largest section, also called the Sleeve), Left channel (the tip of the plug), and Right channel (the connection between the Ground and Left channels, also called the Ring.) Googling 3.5mm pinout should help if you need a visual, I was able to find quite a few that explained the different connections.

[@lordvespatron]

How do i set this up to display the lissajous pattern? Please.. i have a mono output, sleeve and tip to check.

[@brettschacher8644]

It's been a long time since I used a scope but if IIRC you have to couple both the vertical and horizontal inputs to get the scope to do this? The only scopes I saw Lissajous on were not DSOs they were CRT analog units

[@overbuiltautomotive1299]

i been looking at theses please can one get a video out to hook this to a vga monitor or ?? old tv bigger screen using diy board i understand electronic just do not mess with this stuff much help as i need a bigger screen on this toy

[@TinkeringWithTerrius]

I'm sure there is some way to hack the display signal and send it to an external source, unfortunately that is way beyond my current skill set. You'd have to figure out a way to take the data for the LCD and send it to a VGA or component video converter while also translating it into data that converter could understand. I imagine it would require knowledge of the DSO138's firmware in order to know what standard they are using for the display signal. It would be a very interesting hack (being able to use an external display would be amazing), alas I wouldn't have a clue on where to begin a project like that. If you do figure out how to do it, or find information from someone who has I'd love to hear about it!

[@jamielamatocinos9257]

hi, it can be used to the ac and dc voltage? is the waveform indicates the flow of current?

[@TinkeringWithTerrius]

Yes the DSO138 can be used to measure either AC or DC, An oscilloscope measures Voltage over Time, the result of the measurement is a visual representation in the form of a waveform. There are ways to measure current with an oscilloscope but those are not it's intended use.

[@wdujsub7902]

you can´t measure current with an oscilloscope but you can measure the voltage across a resistor. just get a very precise resistor or you can get resistors designed especially for that purpose that are called shunts.

[@user-nh7wo3cp8i]

Hi. Thank you very much. Just one question. Is there any way to transfer the saved screen from the oscilloscope to our computer?

[@spicesmuggler2452]

Yes, you take a picture of it with your smartphone

[@user-nh7wo3cp8i]

@@spicesmuggler2452 I knew that. I am looking for a better way

[@a1b2c3z44]

when calibrating, my signal flickers left and right... what is that and how to remove it?

[@TinkeringWithTerrius]

Is the flicker constant or does it only occur while adjusting the trimmer caps? Does it only happen when the trimmer caps reach a certain point in their rotation? It could just be noise causing the signal to jump out of range while moving the trimmers, or it could be defective trimmers, it is hard to say. Mine hasn't had this issue so I am unsure of how to remove it.

[@RespawnRestricted]

i just put mine together and it did not come with that lil loop thinning you talk about at like 1:50 into the vid.. is their anything i can substitute for that ?

[@TinkeringWithTerrius]

The little loop was just a piece of excess wire from one of the through-hole resistors. A small loop of any solid core wire should work just as well.

[@horashia495]

Please answer .. how much volts can it measures? ?

[@TinkeringWithTerrius]

Maximum specified Input voltage is, 50V peak using a 1X probe.

[@ElectroIoT]

@@TinkeringWithTerrius thank you for information

[@TinkeringWithTerrius]

You're welcome, I hope it was helpful.

[@PowerScissor]

This is a really dumb question I'm sure...but I'd rather be safe about it. I wanted to look at a modified sine from a cheap 120V AC inverter with my DSO138 so after researching ordered probes that are 10X. Are those the correct ones or do I need 1/10th probes. 10x makes me think 120V would read as 1200V.

[@engineeringgarage5113]

@@PowerScissor i don't know if you are still looking for an answer but with a 10X probe it will read 120 volts as 12 volts.

[@elyesmehri3067]

Is DSO oscilloscope got any cursor

[@TinkeringWithTerrius]

No, the DSO138 does not have a cursor. It only has an arrow at either side of the screen for adjusting the Vertical position of the waveform/trigger.

[@ankushruyarkar8148]

How much price this sir?

[@jayantanath9]

what is the maximum range of frequency to be measured with this device ?

[@TinkeringWithTerrius]

The manual says 200 KHz. I'm not sure how accurate it is at those frequencies though.

[@daniellee6912]

my readings jump all over the place on smaller scales even with no probes attached, is there a fix?

[@TinkeringWithTerrius]

if it is just noise you might try adjusting the variable calibration capacitors. Otherwise I'd check all of the solder joints to make sure something isn't missed or loose. With no probes attached the signal should be pretty flat, I suppose external RF interference might also be a possibility since this scope has no shielding at all.

[@daniellee6912]

Tinkering With Terrius Thanks, I bought this kit with all the components soldered already, I'll see if adjusting the trimmers make any difference.

[@brettschacher8644]

I just received one of these units and had issues getting solder to stick to the BNC connector. I have posted on a couple of other locations dealing with these kits, anyone else have trouble in this stage? Also having problems getting the USB connector cleanly soldered without shorting all the terminals. I'm using a good iron and .o32 solder. I have noticed there were several other points that were more difficult to solder then what I feel they should have been, it's as if the plating of the joints was the reason.

[@TinkeringWithTerrius]

I remember the BNC being a bit tricky to solder, the thermal mass of the connector made it challenging, similarly with the USB connector (though not nearly as much as the BNC.) It's also likely that the plating used isn't the most compatible for soldering. Patience and a larger wedge tip than I normally use helped me. Looking back at my assembly video, the slide switches were also tricky to solder for me.

[@brettschacher8644]

@@TinkeringWithTerrius Yes I am having a slight issue with the shells of the switches too. I have to go get my dual range soldering gun I suppose and see what results from going from the variable heat soldering station to the 100 watt unit. I need to find some small solder wick or use some vacuum to remove the glob from the USB socket. I also just watched a video on how to improve the noise by re routing a few capacitors. Have you seen this and tried it? I don't want to attempt much with this unit unless I know it is viable to proceed.

[@TinkeringWithTerrius]

Interesting, I haven't seen that mod I'll have to look into it. For my purposes of reading simple signals the noise never caused much of an issue, but I'm curious how effective the mod would be.

[@dimuthumadusanka6994]

Can we measure above 5v dc and 230v ac.

[@brettschacher8644]

Read the specs on the device. Anything over 50V is out of the question unless you construct a Voltage divider system and calibrate it. Anything with an AC voltage would be a good idea to use a capacitor coupling. A 10 to 1 probe would also be a good idea to get. You could construct this

[@mjyanimations1062]

My scope isweird. holding + and - doesn't reset anything andholding ok just switches between hold and run super fast.

[@TinkeringWithTerrius]

Interesting, I wonder if it is a newer firmware, or if there is some sort of hardware issue with your scope.

[@mastercat]

red aligator goes to the signal ..and the black goes where?

[@TinkeringWithTerrius]

The black clip will go to a common ground point on the circuit you are probing. So if you were probing an IC, the red goes on whichever signal pin you are interested in, and the black would go to the ground pin. Not sure how accurate this following statement is, but I was told to think of an Oscilloscope (especially a floating battery powered one like this) like a volt meter that works over time. The scope is measuring and displaying voltage but with a time component, so like with a volt meter you connect to the source that you want to measure with the red probe, and a common reference point (ground or the 0v rail ect.) with the black probe.

[@fajarsan329]

so which one do you think dso 138 or dso 1500

[@TinkeringWithTerrius]

I haven't used the DSO150 personally but from what I've read it is more robust and slightly more accurate. Of course there is also a new version of the DSO138 called the DSO138mini, which is also supposed to be a bit more accurate. The DSO150 looks overall nicer due to its case, prevents having any exposed components. I'm pretty sure the DSO138 wins for pricing though.

[@fajarsan329]

Thanks for your input

[@sureshkashyap47]

Plz sand me hindi vedio

[@bergarteric5713]

ajust your focus !!!! i see nothing !!!but thanks for the share Eric from France

[@nopadolta354]

Can it measure 220VAC?

[@TinkeringWithTerrius]

Short answer is no, the DSO138 has a maximum voltage of 50V peak. In addition to this 50V limitation, I would not trust a cheap DIY oscilloscope for measuring anything with high voltage, it just isn't designed for it. In order to measure mains AC like that you would require a professional scope and a set of mains rated differential probes, in addition to all of the safety prep to make sure that there is no way for mains to short through the scope and burn it up.

[@mfdoom7123]

u can make voltage divider with resistors.

[@brettschacher8644]

Kuman and some other vendors market probes in 10:1 and 100:1 for high voltage use. Since BNC is a standard for scope lead connections they will fit. The only thing I will advise is to be sure the power is off before you get in there and keep hands clear. These scopes are cheap enough to replace if it goes POOF, just be careful. I used to have a scope back in the early 80's and it was NOT a cheap one, it was a pricey BK and I was working on TVs back then. I got to close to a second anode lead in an RCA that had bad insulation. I got hit with 33,000 volts of high frequency pulsed DC and it blew out my scope and I could talk right for a few weeks or move right. My next question is why would you want to use a scope to measure 220 VAC unless you are looking for harmonics from a sycrohnous generator?

[@brettschacher8644]

@@TinkeringWithTerrius If a 10:1 probe is used, then on the 1 v sensitivity setting you should be able to measure up to 500 v. The BNC cable that comes with this kit is a direct coupling. There are 100:1 probes also that allow up to 5kv at 1v / div.