Oscilloscope for (complete) beginner?

[anvoice]

Hello,

I'm a chemistry major, but I like all things technical and would like to learn about electronics.

Since I'm quite serious about learning electronics, I'd like to buy an oscilloscope to help in the process, as well as any projects I'll be doing. Trouble is, despite doing a fair bit of reading on the subject (mainly forums and blog posts), since I don't know exactly what kind of projects I might be doing, I have no idea what kind of scope might be sufficient. I was thinking of picking up an old used model from ebay, but have no idea what features I should be looking for. Is 20MHz enough? Do I need to be worried about the memory depth at this point? Any essential functions that need to be there? Is an analog scope sufficient to start with?

This brings me here with this basic question: which oscilloscope would you recommend for a beginner who is eager to learn but not yet certain what types of projects he'll be working on? I'd appreciate any help and suggestions. If you can recommend other equipment I might be needing (e.g. signal generator or logic analyzer) I'd be happy to hear it, as well as any other general tips and advice.

More Details:
Budget. Preferably not exceeding $100-200: since I don't know exactly what I'll be doing yet, I'd prefer not to spend too much on something I might have to replace in a year as I outgrow it.
Main purpose: learning (e.g. building and testing circuits), but would be nice if it helps in future projects. Some interests include 3d printing (a bit of experience here) and robotics (i.e. working with micro controllers a good possibility).
Many thanks and hope to hear your suggestions.

[BlueBill]

Keep an eye out for a used Rigol DS1052e. You might be able to score one for around $200 if you're lucky.

[tggzzz]

As you have half-realised, the most important question is not "which scope?", but "what am I going to use the scope for?". Therefore the first question you need to answer is "how am I going to determine what I want to measure?".

One way is to specify your first two or three projects, and from that you can determine what type of signals are of interest - analogue/digital, amplitude, frequency.

Another is to buy a cheap simple scope and see what you can and can't do with it. And then you will have a better idea of what you really need. One way or another you will pay for getting the experience; in this case the price is that of the cheap simple scope.

Whatever you choose, understand that scope probes are an integral part of not only the measurement system but also the circuit being probed. Good scope probes aren't cheap - it is easy to find probes costing >$10000. Fortunately you won't need to pay anyway near that! There are plenty of threads on this forum about scope probes, some gontaining good information and pointers to decent literature.

Consider that an old cheap simple analogue scope is probably easier for a beginner to understand than a digital scope. Horses for courses.

[rdl]

Since you're a student, buy an Analog Discovery for $99.  It has more than just a scope and it'll do just fine until you can figure out what you really need to spend big bucks on.

http://www.eevblog.com/2014/12/13/eevblog-692-digilent-analog-discovery-review/

[anvoice]

Thanks for the suggestions.

The Rigol looks pretty good, but seems like seeing it for <$300 is pretty rare. I'd rather get something sooner than later.

As far as the Discovery goes, are there any significant drawbacks to getting one? Seems like a very good deal for $100 if it includes a function generator and logic analyzer.

My first projects are likely to be in 3d printing (making one right now) and robotics, so digital signals are probably more useful, but I'd like to be able to test simple analog circuits as well as I'm learning to build them.

[Paul Moir]

Will need probes (cheap ones from Amazon or Ebay are fine. ~$20 a pair.  10x probes are what you want, not 1x).  Only 5MHz analog bandwidth which will keep you in 1MHz digital territory, which is sort of OK but not great.  You'll need a computer to use it of course.
 
Some Rigol 1052E owners are upgrading to the 1054Z, so there's upcoming deals to be had.  I think there's a couple going for $250 in the buy/sell section of the forum.

Since you're interested in some things that involve digital electronics, I would skip an analog oscilloscope altogether unless you got one super cheap.  A DSO is infinitely more useful than a plain scope when dealing with complex non-repeating waves like you want to see in digital electronics.  Plus you can download them to a computer and analyze them if you need to.

EDIT:  Oh, what I was going to say is whatever you do, do not buy one of those little ~$100 pocket type oscilloscopes you see around.  The true bandwidth is usually horrible, they often do not use proper probes.   1x probes they usually come equipped with load your circuit your testing badly. Save your money.

[tggzzz]

The Analog Discovery is good value for the money, and a good way to experiment to find out what you want.

The major limitation is the scope bandwidth, which will be adequate for any signal associated with "moving objects" - but which won't be good enough to see all digital signals. It will be OK for UART type signals and for signals that are generated by bit-bashing software, but not good enough for general purpose digital logic. As a starting point, think of it being adequate for signals with a bit rate of up to a few Mb/s.

The AWG and patten generator will probably be sufficient, and will continue to be sufficient if you move to a higher bandwidth scope.

The construction is adequate but not hardy, particularly the USB socket.

Get the BNC add-on as well.

[VK5RC]

I would hold off the purchase for a while,  do some projects of different types eg analogue and digital,  see what interests you and go from there.  Other gear eg good DMM,  good soldering station and lab power supply and  a few good hand tools might be a better investment (if you don't have already).

[daybyter]

https://www.eevblog.com/forum/testgear/hantek-6022be-20mhz-usb-dso/

[anvoice]

I'll probably avoid the Discovery then. Would rather spend a bit extra on something with some room to grow.

I think waiting a bit might be a good choice since I can't even use for the device just yet, but if I see a good deal on one of the recommended ones it may be worth getting. I'll keep an eye on the Rigol 1052E to see if one appears for a good price.

The Hantek might be a good value, though there's a SainSmart 20MHz DDS120 model out there that's a bit cheaper and has slightly better reviews from what I've seen. The 20MHz bandwidth seems like a potential deal-breaker for more serious work though.

[tggzzz]

I'll probably avoid the Discovery then. Would rather spend a bit extra on something with some room to grow.

I think waiting a bit might be a good choice since I can't even use for the device just yet, but if I see a good deal on one of the recommended ones it may be worth getting. I'll keep an eye on the Rigol 1052E to see if one appears for a good price.

The Hantek might be a good value, though there's a SainSmart 20MHz DDS120 model out there that's a bit cheaper and has slightly better reviews from what I've seen. The 20MHz bandwidth seems like a potential deal-breaker for more serious work though.

It is worth considering where the next "capability breakpoint" might come. If you are thinking of looking at general-purpose digital logic, then you will need at least 100MHz bandwidth, preferably higher. For digital scopes you can ignore the "samples/second" spec, and should concentrate on the analogue bandwidth.

Be aware that the bandwidth is determined by the digital signal's transition time, not the bit rate. When looking at >100MHz signals, the precise oscilloscope probe and probing technique becomes important. A typical *10 probe with a 6" ground lead will introduce ringing at ~100MHz (the 20pF tip capacitance and 140nH lead inductance), 20pF at 100MHz is an impedance of only 80ohms, nowhere near megohms! Consider using a "low impedance Z0" probe, which will have an impedance of 500ohms and a decent bandwidth too.

[anvoice]

Sounds like the Rigol 1052E might be a good choice then, since it goes up to 100MHz with a simple mod (just a register value change?) I believe.

I don't have the technical knowledge to differentiate different probe types yet unfortunately (just recently read series and parallel resonance) but thanks for the tip.

[anvoice]

For the DS1054Z, $500 seems a bit of a stretch for my current budget and for a learning scope. I'd rather splurge on something like that after I have a good grasp on my actual needs, and when I have other essential equipment (still need to get a variable power supply, etc.).

Interesting suggestion about the simulations, I'll check those out if they're available for free.

[jancumps]

You can ask on this forum if anyone sells his/her scope. A number of members are about to buy the ds1054z, or have just purchased one.
They may have their previous one for sale.

I got mine second hand from a fellow EEVblogger.