$20 oscilloscope are they any good?

I keep seeing ADs for cheap $18 & $20 oscilloscopes are these things worth having?

I don't see any details about voltage or anything about these scopes?

I would like to know more before I buy one?

https://www.gearbest.com/testers-de...8X4t6wtGa8T3tU8Ibzt67pGQUXI-zF7gaAlsvEALw_wcB

gary350 said:

I don't see any details about voltage or anything about these scopes?

Click to expand...

Well, if you scroll down the advert it clearly states:

*********************************************************************************
Main Features
● Can be used as test ARM development board / changed to millivolt-meter, data logger
● Display frequency, cycle, pulse width, max / min, average, peak value and effective value
● With automatic, conventional and single trigger mode, can freeze at any waveform display

Specifications
- Maximum real-time sampling rate: 1Msps
- Accuracy: 12bit
- Sampling buffer depth: 1024bytes
- Analog bandwidth: 0 - 200KHz
- Vertical sensitivity: 10mV / Div - 5V
- Input Impedance: 1 megohm
- Maximum input voltage: 50Vpp ( 1: 1 probe ), 400Vpp ( 10: 1 probe)
- Coupling modes: DC / AC / GND
- The horizontal time base range: 10μs / Div - 50s
*********************************************************************************
Further on down the advert it also clearly states that it is not supplied with a case.

So, if you fancy a bit of adventure, send off your $17,99, wait a while and see what arrives in the post.

JimB

A friend who is a retired embedded electronics engineer replaced a Tek scope with this https://jyetech.com/Products/LcdScope/e150.php one. He is really pleased.

I bought a small DSO201 to use outdoors.... The battery lasts forever and the operation is good I'm well pleased with it.

Downside!!!! The menu is kinda "side scrolling" So to change anything ie vert / horiz resolution, trigger, volts/div etc.. must be separately selected before adjustment!! No big problem though!

Love it!

I have 2 of them & find quite usefull. There is some internal noise shows up, which I just ignore. Picture of what you can expext.

JimB said:

Further on down the advert it also clearly states that it is not supplied with a case.

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I got a Plexiglas case from Ebay for mine. That is also where I got the scope. Think I only paid around $18 for the both of them.

I bought this one. I think it has already been mentioned. Here is the User Manual. Some assembly was required (no trouble). Yes, you should look carefully at the specifications. You can probably find it a bit cheaper (I think I paid less than $26 for it either on sale or with some coupon or something). I did not have to upgrade the firmware as I had the most current version.

I like to "pride" myself on not buying more expensive things until I have "earned" the need and knowledge to use them. That sums up the "why" I bought a toy O-scope. I am happy I did. I have used it more than a few times and it is a useful and convenient tool, in my view. The more I use it, the more I become aware of its limitations and that is actually the expected positive result, which will, likely, lead to a future purchase of a "real" O-scope. That is my thinking and review.

it depends on what you are doing with it. a coworker was using a digital scope, trying to diagnose an audio amplifier that was drawing excessive current, but not so excessive that it tripped the protection. the DSO he was using appeared to have a half of volt of noise at the speaker output. the waveform on the scope looked like noise similar to that on the square waves in post #5 above. connecting an analog scope revealed that it wasn't noise, but a 1Mhz oscillation in the output stage of the amplifier.

Last time I bought something from china instructions were in Chinese symbols. My best VOM instructions is in Chinese. It took a lot of trial and error to figure out which 4 holes the red wire needed to be in and where the selector switch needs to be. Ebay has a scope $17 free postage its hard to go wrong at that price for what I will use it for.

gary350 said:

Last time I bought something from china instructions were in Chinese symbols. My best VOM instructions is in Chinese. It took a lot of trial and error to figure out which 4 holes the red wire needed to be in and where the selector switch needs to be. Ebay has a scope $17 free postage its hard to go wrong at that price for what I will use it for.

Click to expand...

I got mine from Ebay, but it shipped from the US a couple of $ more but the instructions were in English. But then I've had it for a while so price might be higher now.

shortbus= said:

I got mine from Ebay, but it shipped from the US a couple of $ more but the instructions were in English. But then I've had it for a while so price might be higher now.

Click to expand...

They pretty well all come in English, if you get a Chinese one then it's probably a mistake - and if you tell them they will send another. Quite often the pictures on the website show the Chinese version, but it clearly states that an English one will be provided.

This one is not a stand-alone O-scope and it is $29. A board meant to be attached to laptop/desktop. I had been looking into it as a way of using a secondary computer that has given way to a primary and/or an older laptop or tablet. I thought that it had some impressive specs - not sure of that, but it looked that way to me. Decent reviews and open-source are added benefits.

DrG said:

This one is not a stand-alone O-scope and it is $29. A board meant to be attached to laptop/desktop. I had been looking into it as a way of using a secondary computer that has given way to a primary and/or an older laptop or tablet. I thought that it had some impressive specs - not sure of that, but it looked that way to me. Decent reviews and open-source are added benefits.

Click to expand...

Well at first glance the spec looks pretty poor, particularly the scope scope - however, a longer look considering the extra facilities it provides, means it might be worth a look (something else to play with - I'm tempted now ).

Here's a small scope I've recently bought, it claims to have 30MHz bandwidth, and has internal rechargeable batteries - I haven't had time to play with it yet, apart from switching it on and pressing a few buttons.

https://www.banggood.com/DSO338-Han...z-Bandwidth-200M-Sampling-Rate-p-1332155.html

The spec looks pretty interesting, and it's nicely portable.

DrG said:

I like to "pride" myself on not buying more expensive things until I have "earned" the need and knowledge to use them. That sums up the "why" I bought a toy O-scope. I am happy I did. I have used it more than a few times and it is a useful and convenient tool, in my view. The more I use it, the more I become aware of its limitations and that is actually the expected positive result, which will, likely, lead to a future purchase of a "real" O-scope. That is my thinking and review.

Click to expand...

Makes perfect sense.

Is like learning to play golf, you don't go and purchase the most expensive golf clubs available. You can purchase cheap or used ones, and once that you master them, and most important enjoy what you are doing, then you invest on better ones.

EDIT: I can see these inexpensive scopes as excellent tools when you require a "floating" scope, as most can be battery powered.