My first oscilloscope

[mike_mike]

Hello. My name is Mike. I am new to this forum.
I want to buy a oscilloscope for my electronics laboratory.
I don't want to spend a lot of money because my budget is very limited.
I am looking at Atten AT7016. It is about 150 euros. Worth to buy it ? 
Please tell me if you have any experience with this oscilloscope ? 
I want to use the oscilloscope to measure the ripple at the output of a linear power supply.

[tggzzz]

Hello. My name is Mike. I am new to this forum.
I want to buy a oscilloscope for my electronics laboratory.
I don't want to spend a lot of money because my budget is very limited.
I am looking at Atten AT7016. It is about 150 euros. Worth to buy it ? 
Please tell me if you have any experience with this oscilloscope ? 
I want to use the oscilloscope to measure the ripple at the output of a linear power supply.

There are many many threads on exactly this topic on this forum, and some are currently active.

A little research on your part will enable you to formulate questions that will be of direct use to you. Without that you will get standard generic replies.

[tautech]

Welcome to the forum.

Please place your country flag in your profile for local recommendations.

DON'T BUY IT.
It is a CRO and has very limited features for the money.
If you MUST have a CRO get a SH Tek, Phillips, Hameg, HP etc.
Don't buy SH unless you can source Operation and Service manuals.

Everybody these days are getting DSO's for the mass of features they offer.

How large is your budget?

[pickle9000]

Not worth the money.

[ebastler]

DON'T BUY IT.
It is a CRO and has very limited features for the money.
If you MUST have a CRO get a SH Tek, Phillips, Hameg, HP etc.
Don't buy SH unless you can source Operation and Service manuals.

Everybody these days are getting DSO's for the mass of features they offer.

I fully second what tautech has written. Since you may be relatively new to this, and potentially a non-native speaker, I thought I'd add a little glossary:  ;-)

CRO = cathode ray oscilloscope (old style, analog cathoda ray tube - cannot store and display traces of rare events)
DSO = digital storage oscilloscope (digitizes and sores data, display on an LCD display)
SH = second-hand

If our budget is below 300 Euro, a decent second-hand CRO is a good recommendation. You should actually be able to get entry-level models from the good brands tautech has recmmended starting at 100 Euros. If you can afford 300 Euros or a tad more, a DSO offers many additional possibilities. The Rigol DS1054Z currently sells at 299 Euro + tax, and is amazing value. (4 channels, upgradeable to 100 MHz bandwidth, many measurement and trigger options.)

[Muxr]

Yup. If you can stretch your budget to get a DS1054Z, that's what you should get, as it's the best bang for your buck.

If not get a sub 100 euro used analog scope.

Not familiar with it personally but Siglent's SDS1052DL is just above your budget and I think it would be ok as well.

[pickle9000]

If you can only get one scope a dso will do you well. I have a basic Siglent dso and it was worth every penny. I have other scopes I use daily but I use that one in the field. Even if you get another scope in the future it will still have value in the shop.

I have one of the Rigols as well and 1054z is just killing everything close to it's price point. I have more expensive scopes but it's a good everyday scope no question.   

[miguelvp]

+1 on modern DSOs, here is a pictorial example:



vs:





On the analog one, you have to do math to figure out things and you only get OK approximations.
Signal using the x10 magnification in the time base module, so it's 5ns per division.
A 26MHz clock has a period of ~38.46154 ns divided by 5ns that will give me ~7.7 divisions.
Probe is x10 so voltage per division is 10 times larger.

Edit: working it backwards as you would if you didn't know the source signal is.
5ns x ~7.7 divisions = ~38.5 ns
38.5ns / 1000 (us/ns) / 1000 (ms/us) / 1000 (s/ms) = 0.0000000385 seconds
Frequency is the inverse so 1/0.0000000385 = 25974025.974025974025974025974026
rounding off: 25974026 Hz or 25.974026MHz
Error: 25974 cycles per second (Hz). (On a well calibrated scope but you have to rely on your uncalibrated eyes and the lack of divisions that you wouldn't even see if they could display it on the analog scope)

Digital ones just tell you what is what. no fuzzing around

Plus you get more data showing you where noise or ringing is at (both measurements made with the same probe and with a spring ground as close to the OCXO as posible).

Edit: Rigol is not a DS1054z, it's a DS2302 (300 MHz) but the same measurements are available I think on the DS1054z.
Analog is a Tektronix 7613 (100 MHz) and the signal is magnified with the x10 zoom function with time setting at 50ns. Also I had to calibrate the tek by adjusting pots inside the scope, had to do nothing to the Rigol.

Edit2: Don't get me wrong, I love the retro look of the Analog scopes

Edit3: Note that I had to square the signal on the analog scope to actually make the measurements, on the digital one I didn't even bother that much, it takes more preparation on the analog one to actually measure what the signal is showing you.

And this doesn't even touch the milliard other features the digital scopes bring to the table.

[tggzzz]

Digital ones just tell you what is what. no fuzzing around

Oh dear. If only that was true. All instruments lie, albeit in different ways.

Digital scopes do have significant advantages, but quite frankly if you can't interpret a unannotated graph (i.e. and analogue trace) then you should seek employment elsewhere. Maybe as a software "engineer" (and I use that term loosely). In addition, analogue scopes do have significant advantages in some situations, but this isn't the place to rehash that argument.

There is a good argument that analogue scopes are easier for an beginner to understand because all the controls and optional settings are directly visible on the front panel. I've seen too many beginners that are unable to use a digital scope because they didn't realise they needed to tweak the setting buried on the fourth menu of the fifth page.

[miguelvp]

True they lie, but they are more accurate for all purposes.

As for usage, analog scopes have a lot of voodoo in them, digital ones are very simple to use in comparison for the same task.

Ask any of these new guys that never used an analog one what the cal setting in most of the knobs do, they will be clueless.

And how to set the delay or use the x-y. They will get bored by page 10 of the manual and they don't even need to read the manual for the digital ones (even if they should based on some of the questions they ask).

[miguelvp]

But let's not confuse one thing, all scopes have analog front ends and some modern DSOs have sub-par analog parts.

But all being the same, DSOs can interpret the analog front end better than human eyes and they make the measuring tasks easier.

case in point:

Look at this signal:

and come up with the actual frequency
And try the same thing with a 100MHz DSO like the DS1104z Rigol, who is going to be closer?

And that's just one quarter of the scope's "stated" capabilities.

[tggzzz]

True they lie, but they are more accurate for all purposes.

No: "all" is an inappropriately strong word in this context. People have given many examples of that, and I'm not going to rehash them here.

As for usage, analog scopes have a lot of voodoo in them, digital ones are very simple to use in comparison for the same task.

That entirely depends on the task.

Ask any of these new guys that never used an analog one what the cal setting in most of the knobs do, they will be clueless. And how to set the delay or use the x-y.

So what?

They will get bored by page 10 of the manual and they don't even need to read the manual for the digital ones (even if they should based on some of the questions they ask).

Having taught people to use both, I've repeatedly observed that they learn faster and better if they start with an analogue scope. Once they are familiar with analogue scopes, they can make good use of the facilities a digital scope provides, and not fall into some of their traps.

[tggzzz]

But let's not confuse one thing, all scopes have analog front ends and some modern DSOs have sub-par analog parts.

Yes indeed. A 1GS/s scope should, of course, be able to see a 500MHz signal! And there's no way that a 40MS/s scope can see a 1ns edge, is there! How many times have I heard those misapprehensions

But all being the same, DSOs can interpret the analog front end better than human eyes and they make the measuring tasks easier.

Rubbish.

Your statement is true for many common cases with well-behaved signals. But not in all circumstances. I've seen good scopes from reliable manufacturers be extremely misleading unless you realise that it is necessary to tweak that buried setting.

One case that springs to mind was a "show me the analogue eye diagram" of a PRBS signal. The analogue scope instantly gave the correct answer. The digital scope gave a ridiculously wide envelope, unless you knew that you had to change how it postprocessed and displayed the captured signal. And at that point is showed the same display as the analogue scope.

Many experienced analogue/rf engineers prefer to use an analogue scope when first looking at a signal. After they are convinced that "nothing funny is going on", they switch to a digital scope for detailed measurements. The school of hard knocks has taught them to do that.

[Wuerstchenhund]

Having taught people to use both, I've repeatedly observed that they learn faster and better if they start with an analogue scope. Once they are familiar with analogue scopes, they can make good use of the facilities a digital scope provides, and not fall into some of their traps.

I heard that often, but quite frankly based on the large number of apprentices we (where I work) teach I'd say that is wishful thinking. We don't teach them on analog scopes for roughly a decade now, simply because it offers no benefit, and in contrast often caused more confusion than necessary. Most entry level scopes are also dead easy to operate, and students can learn all basics on digital scopes as well, and often even much better, aside from avoiding learning outdated practices that may have been useful in the old days but often are actually counterproductive on modern scopes.

We still discuss analog scopes briefly and explain how they work, but the focus is on tools for this day and age and not for something from the past which has long been obsolete.

I myself did learn on analog scopes during my school days, but was introduced to digital scopes early on. And quite frankly, knowing analog scopes really didn't help me in understanding and working with digital scopes.

[tggzzz]

Having taught people to use both, I've repeatedly observed that they learn faster and better if they start with an analogue scope. Once they are familiar with analogue scopes, they can make good use of the facilities a digital scope provides, and not fall into some of their traps.

I heard that often, but quite frankly based on the large number of apprentices we (where I work) teach I'd say that is wishful thinking. We don't teach them on analog scopes for roughly a decade now, simply because it offers no benefit, and in contrast often caused more confusion than necessary. Most entry level scopes are also dead easy to operate, and students can learn all basics on digital scopes as well, and often even much better, aside from avoiding learning outdated practices that may have been useful in the old days but often are actually counterproductive on modern scopes.

We still discuss analog scopes briefly and explain how they work, but the focus is on tools for this day and age and not for something from the past which has long been obsolete.

I myself did learn on analog scopes during my school days, but was introduced to digital scopes early on. And quite frankly, knowing analog scopes really didn't help me in understanding and working with digital scopes.

I think that is fair comment, except that it isn't "wishful thinking" on my part - it is merely what I've observed.

However I do object to two points that you weren't making:

• that a beginner should avoid a cheap and available scope merely because it is analogue
• that digital scopes are always better

[miguelvp]

Many experienced analogue/rf engineers prefer to use an analogue scope when first looking at a signal. After they are convinced that "nothing funny is going on", they switch to a digital scope for detailed measurements. The school of hard knocks has taught them to do that.

You probably mean, many experienced analogue/rf engineers expirience with the first generations digital scopes, right?
I would not thing you are referring to the last ten years.

But if it's something that has happened recently please do tell and link some info about it because it will make a very interesting read.

Maybe you are right and they use just analog only tech to capture a trillion frames per second being able to capture light traveling.

One thing is true, the world is analog but right now we must rely in the digital domain to make use of that analog information until someone comes along with an more efficient analog only counterpart.

There must be a way to compensate for the unwanted noise.

And yes, a digital scope with the same analog front end is better than a analog only scope, there is no doubt about that.

[franksanderdo]

hmmmm.....

I am not yet sure that the (starting) argument will help mike_mike in his decision process.
Knowing that all of you are much more experienced than I am, maybe you can help me out:

Is it possible to build a kind of budget table which would give a hint for mike_mike?
Something like:
<= 50USD no chance, forget all the crap
<= 200USD some second hand CROs or some entry DSO (Hantek???) with the a/b/c limitations
<= 500USD entry level DSO i.e. DS1054 ...

maybe this approach can help newbies as a starting point and then they have to investigate further?

All the Best
Frank

[Michaela Joy]

@mike_mike: IMHO, buying an oscilloscope is like buying a car.

You want it to be adequate for your immediate needs, and you don't want to outgrow it too quickly. If you buy a new scope, you get a warrantee. If you buy a used scope, you don't know what the previous owners did to it, and you don't know how long it will last before it needs to be repaired. If you buy an older scope, you may not be able to fix it, or the cost of repair may very well be too high to justify the purchase.

As far as analog vs. digital scopes, each has it's place in the lab. If I could, I'd buy one of each. The ability to capture a sporadic event can be -very- handy.
But good digital scopes are not cheap. Neither are good analog scopes.

What area are you looking to work in? Digital? RF? Audio stuff? Do you need to see signals above 100mhz? The answers to these questions will help you decide what to buy.
Also, try to learn as much as you can about oscilloscopes, How to use them, and what their limitations are.

IIRC, there is an oscilloscope video posted here. Find it, watch it, and learn as much as you can from it.

Only then can you make an intelligent decision as to what's best for your lab.

:MJ

[Fungus]

hmmmm.....

I am not yet sure that the (starting) argument will help mike_mike in his decision process.
Knowing that all of you are much more experienced than I am, maybe you can help me out:

Is it possible to build a kind of budget table which would give a hint for mike_mike?
Something like:
<= 50USD no chance, forget all the crap
<= 200USD some second hand CROs or some entry DSO (Hantek???) with the a/b/c limitations
<= 500USD entry level DSO i.e. DS1054 ...

maybe this approach can help newbies as a starting point and then they have to investigate further?

There's not much point IMHO.

If we draw a graph with price vs. value for money there will be such a HUGE hump where the DS1054Z goes that you'd be silly to buy anything within $200 either side of it.

That pretty much rules out anything cheaper than the DS1054Z as being "good value for money" and you pretty much have to go up to something with 2Gs/sec to get anything better.

Maybe if you can get an analogue scope for under $100 then it will keep you going while you save up for your DS1054Z, but, otherwise... keep saving up!

A good bet is to find local electronic clubs, etc., and talk to people. Many of them have dozens of old analogue CRO scopes piled in their garage and would be happy to let you have one if you can convince them you're a good home.

[Wuerstchenhund]

I think that is fair comment, except that it isn't "wishful thinking" on my part - it is merely what I've observed.

Fair enough, and I'm sure that learning on analog scopes was actually a benefit when digital scopes were still in its early days and analog scopes were still the dominant type of scope. But that hasn't been the case any more for a very long time.

However I do object to two points that you weren't making:

• that a beginner should avoid a cheap and available scope merely because it is analogue

I didn't, because a beginner (especially if he/she wants to grow in EE) is generally better served with a modern entry level DSO than with an analog scope.

Of course, if it's really cheap (i.e. <$100) and someone wants it for curiosity/interest then get an analog scope, why not. It can still be fun! But as a "learner's scope" it's no longer ideal as it doesn't teach techniques and appreciation for modern day scopes, which is what they *will* have to work with eventually.

Even if someone is severely cash-strapped I'd recommend to rather save a bit longer and get a DSO than sinking $100 or so in what essentially is a museum piece with very limited use.

• that digital scopes are always better

Well, I'm sure one could construct a situation where an analog scope would still be better (i.e. something where beam intensity modulation aka Z input is required, something that is usually absent from digital scopes, although I'm sure that these days there are other alternatives for such tasks), but the reality is that there is essentially *zero* demand for new analog scopes for over a decade, and for that reason no-one makes them anymore. It's a simple fact. And it hasn't resulted in professional labs hording analog scopes, or prices for analog scopes skyrocketting, again simply because it's a obsolete tool that no-one really wants to use anymore.

And frankly, considering what good digital scopes can do, this is hardly surprising. You really get a lot more information from a good DSO than even the best of the best analog scopes can give you. And it's not that the analog scope isn't occasionally lying to you, because it is. Users are often lured into a perceived "precision" that isn't there and merely exists in their minds.

Many experienced analogue/rf engineers prefer to use an analogue scope when first looking at a signal. After they are convinced that "nothing funny is going on", they switch to a digital scope for detailed measurements. The school of hard knocks has taught them to do that.

Well, I would say that either these RF engineers work in a very poorly equipped lab which only has some crap or antique DSOs, or they simply don't know how to use a DSO properly, which quite often is because people transfer things and practices learnt from analog scopes to digital ones without real appreciation of how a DSO works and what techniques are actually appropriate.[/list]

[Fungus]

the reality is that there is essentially *zero* demand for new analog scopes for over a decade, and for that reason no-one makes them anymore. It's a simple fact.

Farnell lists 10 of them, from various manufacturers:

http://es.farnell.com/webapp/wcs/stores/servlet/Search?st=osciloscopio&catalogId=15001&categoryId=700000027004&langId=-5&storeId=10176


1150€ for a 2-channel, 20MHz 'scope?? 

http://es.farnell.com/gw-instek/gos-622g/oscilloscope-bench-2ch-20mhz/dp/2450060

[Wuerstchenhund]

Farnell lists 10 of them, from various manufacturers:

http://es.farnell.com/webapp/wcs/stores/servlet/Search?st=osciloscopio&catalogId=15001&categoryId=700000027004&langId=-5&storeId=10176


1150€ for a 2-channel, 20MHz 'scope?? 

http://es.farnell.com/gw-instek/gos-622g/oscilloscope-bench-2ch-20mhz/dp/2450060

That looks more like old stock (and Farnell probably would rather keep it indefinitely at list price than selling it off very cheaply). As far as I know R&S (Hameg) has ceased analog scope production a while ago (IIRC the HM400 was their last one, mostly made for "emerging markets"), and I'd be surprised if the others are still in production (i.e. the Digimess is from 2003).

I guess they are still marketing the remaining units instead of throwing them away but I seriously doubt that there are still factories pushing out those things.

And it's not that any of the scopes listed are even good analog scopes, they all seem to be made to lowest costs, with mostly pretty poor specs. Unless it's really for some crude task where a digital scope is definitely not an option (if such thing even exists), anyone who seriously considers buying one of those needs his head examined.

[Rupunzell]

Something to consider about CRT analog scopes -vs- DSO. This was written by Paul Rako at EDN. There are very good reasons why more than a few veteran engineers seasoned by decades of real world stuff still like analog CRT scopes and will use a DSO when the need is there. The both have their place in the world of T & M.
http://www.rako.com/Articles/43.html

This was published not too long ago in EDN.
http://www.edn.com/design/test-and-measurement/4389436/Readers-speak-out-about-their-favorite-instruments

"Reader BobL also prefers analog oscilloscopes. He’s managed to keep two Tektronix 7904 analog oscilloscopes running in his lab. “Transients are sometimes impossible to see with a digital scope, but analog display is great.” An engineer using the name Opcom also has two Tektronix 7904s. “Lets face it,” Opcom wrote, “digital ones update sloppily and nothing is as good looking as an electrostatic deflection CRT. Digital scopes are useful for many things but the trace on a CRT can be interpreted in more ways than the digitized LCD image.”

Based on the comments, I conclude that there is a whole group of engineers who still prefer analog oscilloscopes no matter how much digital oscilloscopes have advanced. Dave McGuire even had a message for the oscilloscope makers when he wrote that his favorites are “My Tek 2465A and 7904A oscilloscopes. Yes I have some fancy digitizing scopes (the Tek 222 is very handy on the road!) but nothing beats an analog scope for fast transients...analog and digital scopes are completely different instruments. Are you listening, Tektronix and Agilent?”


Keep in mind, these comments are from folks who are working engineers at large corporations who can afford and has the most current test toys, yet more than a few are still using their decades old Tek & hp stuff.

Bernice

[smjcuk]

Not a fan of new digital scopes. Four reasons I won't buy one as an amateur:

1. Reliability. Check eBay. Every cheaper second hand one I've seen has dead channels/amps. Doesn't matter if its Rigol or LeCroy or anything inbetween. This leads on to...

2. Complexity. The things are basically a small analogue front end, an FPGA and a computer. Also its all SMD devices and difficult to repair. Channel gone? Good luck fixing it out of warranty without a rework station and an expensive Farnell order (if you can actually get the parts in that small volume). Maybe aliexpress has the part: 29 day lead time...

3. Crippleware. The hardware of the cheap stuff is capable but to tier the devices so you can pay for what you need and they can sell a small selection of base hardware configs, so you have software licenses to deal with. Or in the case of Tek, expensive feature modules that don't do anything other than switch a feature on. I think Rigol do this with license keys. Buy a Ferrari, find its limited to 60mph, then spend another $6000 on the 1000mph upgrade? Nope - no thanks.

4. Trust. The first thing my electronics lecturer said to us at university was that "all equipment tells fibs and lies". To have vast swathes of information presented to you relies on certain algorithmic and mathematical assumptions which aren't really well documented. Coming from a professional software/math background this is a surprisingly complex and error prone area. There are as many rules as your average analogue scope there to consider. To package this up in something entirely trustworthy isn't possible. Perhaps 90% accurate but that's short enough not to want to make any assumptions about. A fine example is determining the frequency of a complex wave isn't as straightforward as it makes it out to be, even with an FFT in front of it and a tick on the feature list.

If I was doing it professionally I would buy a new DSO. Then write it off as operating expense when it dies but as an amateur the investment is a bit of a problem.

[tggzzz]

Something to consider about CRT analog scopes -vs- DSO. There are very good reasons why more than a few veteran engineers seasoned by decades of real world stuff still like analog CRT scopes and will use a DSO when the need is there. The both have their place in the world of T & M.

http://www.rako.com/Articles/43.html
http://www.edn.com/design/test-and-measurement/4389436/Readers-speak-out-about-their-favorite-instruments

Keep in mind, these comments are from folks who are working engineers at large corporations who can afford and has the most current test toys, yet more than a few are still using their decades old Tek & hp stuff.

Those are sensible, balanced points and articles - since they note both types have advantages and disadvantages.

Anybody that claims one is "better" that the other must either state when it is better, or be thought to be ignorant and/or unreasoning.