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Beginner oscilloscope , opinions?

skeer

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I’ve got a chance to pickup a os-121c/usm-140 scope for $40. Guy says it works like it should.. idk yet about what cables or adapters or how many probes he has with it but.. what do y’all think?
 
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rancherbill

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Kezorm

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Had to look that up. Old. Don’t bother unless you’re looking for cool looking vintage paperweight. Sure, it might still work, but you’ll find far more functionality and usability in modern <$500 digital scope. Look at Rigol or Siglent or low end Keysight.
 

Bert_

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A scope is something I would like to have. Honestly at $40 if it's local and it works then why not try it. Not everyone needs a super fast scope. I know I would like to stay under $150 if I ever buy anything. More than that and I just don't need one, it's just a hobby.

Guys recommending $500 price points when the op was looking at something for $40, comical...
 

richfinn

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If you have an old windows laptop kicking around just buy a PICO 2000 series, you can download the software free and practice with it from the PICO website and see if you like it before you buy.

You don't need the fancy automotive version if you're just playing with electronics projects.

 
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skeer

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nope, no Windows in my house lol. But I’ve seen the usb types, may e I’m prejudiced but they look like cheap junk. Which usually I’m fine with.. perhaps they aren’t as bad as I’m thinking?
 

RPH

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One of the better features of the newer low cost scopes is isolation from line voltage. In the old days of plug in tektronix scopes you always carried a ground cheater. This allowed the scope to float in reference to ground. Using two channels in a differential probe set up will cause the scope chassis to be live. That’s why we carried cheaters. New scopes the channels are isolated. The trigger setup is another critical area of scope work. Newer scopes get you in the ballpark quickly. Then you can hone in on the area of concern. Old scopes, not so much. We had one signal that was a bear to capture. It was all in the trigger level being perfect. This gives a higher degree of protection to the users. Be safe, one er visit for electric shocks turns to an overbite hold. The watch the heart rhythms.
 

richfinn

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nope, no Windows in my house lol. But I’ve seen the usb types, may e I’m prejudiced but they look like cheap junk. Which usually I’m fine with.. perhaps they aren’t as bad as I’m thinking?

Actually they work with MAC/LINUX OS too nowadays.

The PICO hardware is perfectly decent for the cost (these are entry level beginner tools, you can spend a lot more on a pico if you need the extra capability), what really blows everybody else out of water is the picoscope software (which is free) and has been developed over the past 30 years in the UK (no poor Chinese translation) and the wider pico community sharing tips, tricks and waveforms etc.

Link to free downloads, 2204 is the most basic cheapest scope

 
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Stuart in MN

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You should mention what uses you have in mind, since different applications have different requirements...for instance, others have mentioned 100 MHz or multi channel capability, but if all you're looking at are basic household current or automotive testing those things may be overkill for your needs.
 

MBfreak

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I have been using scopes for 65 years. First was a Heathkit kit scope. Useful .
My all time favorite is a Tektronix 465 with top box. Have two.
I have tried a few modern scopes with LOTS of functions, many of which ****.
Useful for digital circuits only. I had 2 different which I palmed off
Working with low level analog circuits impossible. They radiated upp to 14 MHz
worse than the cheapest LED armature.
However, had a HP top of the line 4 channel digital at work. $22.000 . Best scope I ever tried.
But not something for hobby.

Ola
 
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Innovate1

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You should post what you intend to do with it as that makes a difference. The OP is a boat anchor. Almost positive it has tubes so if those go out you will have the difficulty of finding a replacement. If you like the cool factor then go for it. But you could get a decent modern scope for about $100 (a bit of a guess). As for accessories you need some scope probes - 10:1 probes load the circuit less. If you are just doing low frequency stuff say 100kHz and below you could get by with some BNC to clip lead cables. Most scopes are non-isolated so if you are working on line voltage stuff you may need to think about that.
 
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skeer

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Yeah my intended or expected usage would be an important point. So here they are:

I don't know.

(lol) Ok seriously though.. I guess primary was to learn at least the basics.. But also I recall going thru a long thread on a TM controller. All evidence pointed to the opto-coupler, the guy asked me if I had a scope. I said no. He said, whelp, might as well scrap it then. So that coulda been a use case.
<sigh>
The more I talk about it the sillier I sound by aiming for what I have been. The Pico would be entirely sufficient, I just have a tendency to go whole hog.
 

P0234

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I'd spend that $40 to something like Scopy (android app) and a Rasperry Pi Pico. The features built into Scopy for signal analysis seem way above and beyond what an old scope can do.
 
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Innovate1

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Nothing wrong with wanting to learn something you have limited knowledge about. It's a quite good goal actually. A quick google of "low cost oscilloscope" turns up some that look fine for basic work like this one at $50 (I haven't looked too closely at it so not recommending this particular one - it's just an example)
https://www.amazon.com/Oscilloscope...Generator/dp/B0BXC6XZVS/?tag=atomicindus08-20

If you go to about $200 you can get some impressive performance for the cost (speaking as someone who uses 20k+ scopes at work regularly).

The last thing I would want to do if trying to learn an instrument like this is fighting with a very old unit where I had to wonder if I was doing something wrong or if there was some problem with the instrument.
 

stioc

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I would say a Pico 2000 series is prob the best bang for the buck. As mentioned above the real benefit is their software (granted their automotive version is not free but you don't really need it) and the large community. I don't have one (because I have others) but I still use their software to look at others' waveforms to compare. I have two scopes; a SnapOn Modis 4-channel, a Hantek desktop unit and a graphing automotive multimeter. I don't use them very often but they each have their place. For a quick snapshot of a signal I'll grab the multimeter as I usually already have it out when doing basic troubleshooting so it's the quickest. For fast signals I'll use the Hantek DSO and if I need 4 channels or longer capture specifically for automotive use I break out the Modis, the drawback of the Modis is the bootup time since it's not 'ready to go' when I need it but that's just me being lazy.
Over the past weekend I was troubleshooting an aftermarket stereo that wasn't producing sound...the very first think I checked for was low-level output from the stereo...all I needed in this case was my desktop variable power supply and the graphing multimeter.
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1715873670369.jpeg
 
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Citation

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I have an Agilent 5462x family scope. It's a digital scope but the last of their green screen CRT models. It does some things really nicely even by modern standards. Scopes in that family are around $100 on eBay all the time. If you want something that is cheap yet great for both old analog work and some digital they are good options. However, the modern lunchbox scopes that can be had for $300-400 are really good and for a lot of micro controller work the USB digital systems are great low cost options. When I bought mine the price was around $200 and the $400 scopes were typically 2 channel, jobs with low resolution 360x240 screens and limited refresh rates. I can't see getting an old analog scope unless you have a specific need/use/want.
 

Etchase

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Grab it. You most likely won’t be debugging GHz designs. That scope will be fine with anything analog.
 

CoogarXR

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I just use a scopemeter. I sold my big ol' CRT Tek scope and bought this one:


I don't use it too often, but it gets the job done. I looked on amazon, and it's only like $65 now.
 

richfinn

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I kinda like that.. could always use another multimeter function too.

Before you pull the trigger on a scope/scope meter consider this.

With a Pico you decide how big the display screen actually is (bigger the laptop bigger the screen). Bigger is gooder!!!!

How intuitive is it to actually use?, Pico software is pretty easy to learn if you speak English and very customisable to your taste and has lots of preset tests included (at least the Automotive version does)

If your going to be trying to learn some crazy Chinese software or button menu shuffling an Amazon scopemeter good luck (it will probably work eventually but it won't be fun and you won't remember what the hell you did and will have to relearn it every time you switch it on).

If you learn new stuff from YouTube you want the popular one that everybody else uses (Pico just has more content).

If it goes "**** Up" you can speak to somebody about it in a language you understand!!!

I would also recommend the "Gadgets Playlist" on YouTube to learn about the Android based "H-Scope" as an alternative to Pico (I'm not trying to sell you anything, just sharing my experience of an average self taught schmuck who has owned a fair few overpriced scopes for automotive testing).

If I bought another scopemeter it would be a Fluke (currently have an OWON which is good value but very complicated to alter the voltage/time base/triggers compared to my Pico)

Anyway good luck, don't be put off it's a fairly easy skill to learn (with caveats), very educational and extremely rewarding 👍
 

Chukster

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I just use a scopemeter. I sold my big ol' CRT Tek scope and bought this one:


I don't use it too often, but it gets the job done. I looked on amazon, and it's only like $65 now.

I picked up a Fluke Scopemeter several years ago, maybe around $100 or so from da 'Bay, tho I had to replace the battery. Less than $150 I'm in for. Should last me a long time, and it's so portable. More so than a Tek 465 with matching scope cart! Long gone are the days of scopes with CRTs that had to be deeeeep.
 

RPH

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I picked up a Fluke Scopemeter several years ago, maybe around $100 or so from da 'Bay, tho I had to replace the battery. Less than $150 I'm in for. Should last me a long time, and it's so portable. More so than a Tek 465 with matching scope cart! Long gone are the days of scopes with CRTs that had to be deeeeep.
I have two fluke scope meters. I find the screens update too slowly for me. I found the four trace color scopes tbs series to be much nicer with a larger screen. Weight was lighter than the scope meters. 4 channels in color is beautiful for trouble shooting.
 
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