Which oscilloscope for hobbyist?

[gojimmypi]

Hello!

I know I'm not the first to ask "which oscilloscope"... but here's my story:

I’ve been researching a good oscilloscope to buy. My last one was a hand-me-down Tektronix, so massive that it had two handles.  (and you really needed to grab with both hands!)

I have plenty of experience with "real" oscilloscopes, although none with what would be considered modern technology, and certainly no experience with a USB device.

My background is in electronic engineering – at one time industrial process controls and monitoring systems, although professionally these days I’m purely a software engineer.  In my spare time I enjoy learning and experimenting with Raspberry Pi, Arduino, MSP430, Bus Pirate and various other electronic gizmos.

I’m looking for a good hobby-grade oscilloscope, and perhaps even a logic analyzer included or separate. I know that many online comments seem to indicate that USB oscilloscopes should be avoided. But I wonder how many of the authors of those comments are serious professionals with requirements well beyond what I would need?

So here’s what I am looking at (in no particular order):

Link Instruments MSO-19 http://shop1.usbdso.com/MSO-19-MSO-19.htm

Analog Arts SL917 http://www.analogarts.com/selection-guid/oscilloscope-with-arbitrary-waveform-generator-and-logic-analyzer/sl917-100-mhz-oscilloscope-10-mhz-awg-100-mhz-logic-analyzer

QuantAsylum QA101 https://www.quantasylum.com/content/Products/QA101.aspx

BitScope http://www.bitscope.com/product/BS10/

Saleae Logic 8 https://www.saleae.com/

and of course:

Rigol DS1054Z (DS1074Z Plus?) http://www.rigol.com/prodserv/250/

For a “real” oscilloscope, it seems the Rigol is the hands down winner. Also the most expensive of the above list;  Also the most portable.

I'm wiling to pay for a good solution, but I'm fairly certain I don't need a $1000+ setup to use occasionally at home. It also doesn't need to be portable.

For the specifics listed above:

I only recently stumbled upon the Analog Arts; looks cool, but not a lot of other comments found online.

The QuantAsylum I have been looking at for quite some time, but the QA101 still seems to be not yet ready for actual sale.

BitScope. People seem to either love it or hate it.

Saleae. Seems cool. American made.

Any feedback, comments or suggestions would be appreciated.

Thanks in advance

gojimmypi

[Howardlong]

Of all of those, the DS1054Z in its altered state has to be the overall winner in my book.

The Bitscope is a bitshite mostly down to the software. Hardware's well built though.

The Saleae is over ratd in my opinion, there is very limited triggering capability, and you need the much more expensive pro models for reasonable sample rate.

I don't know about the other models other than a quick glance, but I'd be confident in saying that if you had a DS1054Z and any of the others, the only one that would be sitting on your bench after a week would be the Rigol.

[gojimmypi]

thanks for your comments.

"bitshite" - that's funny; I learned a new term.

is it the annoyance of having to fire up a PC that makes USB 'scopes so unappealing?

could you clarify "altered state" with regards to the DS1054Z ?

[nbritton]

I know that many online comments seem to indicate that USB oscilloscopes should be avoided. But I wonder how many of the authors of those comments are serious professionals with requirements well beyond what I would need?

The root problem with USB devices is that a general purpose desktop environment is very cumbersome with a complex instrument like an oscilloscope. It's awkward and time consuming when compared to simple knobs and buttons. It becomes very tedious to click on hundreds of different things to control your instrument, imagine what it would be like to point, click, select from drop down box, re-point, click, select from drop down box, re-point, click, select from drop down box, etc. hundreds of times and you can begin to get a feel for the problem. The second problem is the lag, on my Analog Discovery it feels like it takes over 100ms from the time I click on something for that action to take effect, it also lags at updating the screen. I love my Analog Discovery, but I wouldn't use it as my main instrument.

So here’s what I am looking at (in no particular order):

Link Instruments MSO-19 http://shop1.usbdso.com/MSO-19-MSO-19.htm

Strong no. It is limited to a single shot sample rate of 200 MSa/s. This will limit you to a usable bandwidth of about 40 MHz (200 MS / 5 = 40 MHz). If you choose to go with a USB instrument make sure it uses USB 3.0 at a minimum.

Analog Arts SL917 http://www.analogarts.com/selection-guid/oscilloscope-with-arbitrary-waveform-generator-and-logic-analyzer/sl917-100-mhz-oscilloscope-10-mhz-awg-100-mhz-logic-analyzer

Strong no, limited to a single shot sample rate of 100 MSa/s. Disregard bandwidth, single shot sample rate is king when it comes to digital oscilloscopes. For every MHz bandwidth you need preferably a minimum of five times the sample rate to faithfully reproduce a waveform. i.e. 100 MHz bandwidth requires 500 MSa/s. The more samples you have the better, for instance, I bought a 4 GSa/s (4000 MSa/s) scope. You need extra sampling to prevent aliasing.

QuantAsylum QA101 https://www.quantasylum.com/content/Products/QA101.aspx

Strong no. Again, the problem is it's limited to 200 MSa/s. You would need a USB 3.0 interface to get higher sampling rates.

BitScope http://www.bitscope.com/product/BS10/

Strong no. Yet again, the problem is it's limited to 100 MSa/s. Without the sample rate to support it, the 100 MHz bandwidth rating they claim is essentially a lie. Nyquist requires an absolute minimum of 200 MSa/s with a sin(x)/x interpolation algorithm to reproduce a 100 MHz signal, anything less and you will be aliasing. I can not over stress how important it is that you have a high single shot sample rate. sub-sampling/equivalent time sampling are NOT the same thing as single shot/continuous sampling.

Saleae Logic 8 https://www.saleae.com/

It would make a mediocre logic analyzer, but as an oscilloscope it's pure crap. The analog side is limited to 10 MSa/s! Hell no. As an LA, you would need the Pro version to get good results.

and of course:

Rigol DS1054Z (DS1074Z Plus?) http://www.rigol.com/prodserv/250/

This is the only product you've listed that has an acceptable sample rate. If these are your only choices the Rigol is the clear winner.

For a “real” oscilloscope, it seems the Rigol is the hands down winner. Also the most expensive of the above list;  Also the most portable.

I'm wiling to pay for a good solution, but I'm fairly certain I don't need a $1000+ setup to use occasionally at home. It also doesn't need to be portable.

About a month ago I was in the same boat you are in, and yesterday I ended up plopping down $2594 for a Rigol MSO4014. This was the minimum that I felt was necessary to do this hobby justice. I evaluated the Rigol MSO/DS1000Z and honestly I thought it felt like a toy, but it may work for your needs. I also evaluated the Rigol MSO/DS2000 and this would have been perfect, if only it had 4 channels. I don't think you want to spend what I did, so what I would recommend for you is the Rigol MSO2072A, right now this scope is selling for $929.25 over at www.tequipment.net with a special 25% off code. PM me and I can send you the code. If you don't have a signal generator the MSO2072A-S might be a better option for you. I highly recommend the Rigol's because that is what the community knows, everyone flocked around them because nearly all of them are hackable to higher bandwidths. For instance, the MSO4014 that I bought can be hacked to 500 MHz, on a western made Keysight 500 MHz would cost you $14k, so the Rigols offer extremely good value for the money... exactly what a hobbyist wants.

The following Rigol models are all 25% off right now at tequitment:

DS1074Z-S
DS1102D
DS2072A-S
DS2102A-S
DS2202A
DS2202A-S
DS2302A-S
DS4012
DS4034
DS4054
DS6062
MSO2072A
MSO2072A-S
MSO2101A
MSO2102A
MSO2302A
MSO2302A-S
MSO4014

[FlyingHacker]

Stick with a CRT and get a Tek 2232 Dso. Wonderful scope.

If need bells and whistles, and scopes that wipe your a$$ then maybe the Rigol. Otherwise I would stick with an old school scope.

[CustomEngineerer]

Stick with a CRT and get a Tek 2232 Dso. Wonderful scope.

If need bells and whistles, and scopes that wipe your a$$ then maybe the Rigol. Otherwise I would stick with an old school scope.

I've got a Rigol and I've never been able to get it to wipe my ass, though the probe hooks are wonderful for picking dingleberries. Any idea how much Rigol sells the wiper upgrade for? If the Rigol rep would have mentioned that I would have definitely preferred to have that option over the AWG.

I have plenty of experience with "real" oscilloscopes, although none with what would be considered modern technology, and certainly no experience with a USB device.

My background is in electronic engineering – at one time industrial process controls and monitoring systems, although professionally these days I’m purely a software engineer.  In my spare time I enjoy learning and experimenting with Raspberry Pi, Arduino, MSP430, Bus Pirate and various other electronic gizmos.

I’m looking for a good hobby-grade oscilloscope, and perhaps even a logic analyzer included or separate. I know that many online comments seem to indicate that USB oscilloscopes should be avoided. But I wonder how many of the authors of those comments are serious professionals with requirements well beyond what I would need?

It really depends what you are wanting to do with it. I think a little more details about what exactly you are wanting it to do would help people make a suggestion. In addition to asking I would also suggest looking through a couple of other threads on this subject to really get as much info as you can before you decide to spend your money.

I know at least a couple of the usb scope manufacturers (for sure picoscope) have demo's of the software that comes with their instrument that you can download for free to get a feel of what using it would be like. The quality of the software has always been one of the biggest complaints I've heard about the usb scopes/LAs. After trying a couple software demos is when I decided that I really wasn't interested in a usb scope.

Also, if you do end up deciding to get a USB scope, getting one with USB3 is a good idea, but when I was researching them around a year ago most of the ones that had 3 charged a premium for it and some didn't even take advantage of it.

edit: The usb logic analyzers seem to get recommended more than the usb scopes. I've very rarely seen someone actually recommend getting a usb scope on this forum.

[TheSteve]

I'm not a big Rigol fan but several friends who wanted a scope for hobby purposes have bought the Rigol DS1054z, done the free 30 second mod to up the bandwidth to 100 MHz and add the advanced features and all are very happy. I have one as well and an very impressed for the price. You'll even get a discount for being an eevblog member if you buy from tequipment.net
There are many choices but for the price point it's going to be very tough to beat the 1054

[nowlan]

Stay safe with the herd. The rigol is best bang for buck.
4 channels lets you deal with SPI bus, since you seem to be into digital/microcontrollers.

The problem with USB devices is driver support if you upgrade your OS etc.

[EEVblog]

I don't know about the other models other than a quick glance, but I'd be confident in saying that if you had a DS1054Z and any of the others, the only one that would be sitting on your bench after a week would be the Rigol.

Yep, I'd bet that way too.

[gojimmypi]

First, thanks for all the great responses, particularly since I'm not the first to ask the "which oscilloscope" question. 

Stick with a CRT and get a Tek 2232 Dso. Wonderful scope.

yes, the scope I used at work a bunch of years ago was a Tek and the 2232 looks like a similarly priced one  as compared to the Rigol (but used?), and wow... 15 years old. surely things have evolved since then, and the Rigol has twice the number of inputs. Still, hard to go wrong with a Tek, eh?

http://www.tek.com/datasheet/2232-digital-and-analog-oscillscope

The root problem with USB devices is that a general purpose desktop environment is very cumbersome with a complex instrument like an oscilloscope. It's awkward and time consuming when compared to simple knobs and buttons. It becomes very tedious to click on hundreds of different things to control your instrument, imagine what it would be like to point, click, select from drop down box, re-point, click, select from drop down box, re-point, click, select from drop down box, etc. hundreds of times and you can begin to get a feel for the problem.

yes, that's exactly the explanation I was looking for. Dave's video clearly demonstrates the cumbersome interface. That's the kind of thing one never really understands until experiencing it first hand (or seeing someone else). Thanks for the comment.
 

The second problem is the lag, on my Analog Discovery it feels like it takes over 100ms from the time I click on something for that action to take effect, it also lags at updating the screen. I love my Analog Discovery, but I wouldn't use it as my main instrument.

I am so glad you mentioned this! I was looking at the Analog Discovery device some time ago, and had forgotten about it. Dave has an awesome video on this:
https://youtu.be/Aymumu3mYl8

I thought it was cool when reading online, but after watching Dave's video, I think I'm sold on this!

what I would recommend for you is the Rigol MSO2072A, right now this scope is selling for $929.25 over at www.tequipment.net with a special 25% off code.

Thanks for this suggestion. After your comment, I looked very seriously at one of the higher-end Rigols. I'm not sure I want to spend that much, not to mention Dave has a compelling argument to not get the MSO:
https://youtu.be/MC9_4mpqVgU

If you don't have a signal generator the MSO2072A-S might be a better option for you.

This was another great suggestion. The signal generator I have (one-of-a-kind, that I custom built years ago and packed away in the garage), is probably not a great piece of equipment in today's world. So I looked really hard at the Rigol's with the built in signal generator and/or the MSO feature.

Dave made a really good point about how 16 channel logic analyzers today are not needed as much as a couple of decades ago (like when I was getting my degree; the only place I've ever used a logic analyzer was in school); As Dave pointed out: Not a lot of equipment designed these days is full of separate, discrete chips... do I really need that many channels? so I'm thinking the 3 or 4 channels on the Rigol should do for most occasions, and the Analog Discovery for occasional tinkering with more channels.

So in the end, I'm thinking the awesome-price Rigol DS1054Z as my go-to scope, plus the Analog Discovery device for the occasional signal generation and logic analyzer. What do you think?

[usagi]

i've done the cheapy scope thing before, they are all too compromised and usability blows.

finally got a rigol DS1054Z and never looked back.

[Muxr]

Yeah it's not even close really. Rigol's DS1054z changes the game at that price point. 1Gs/s 4ch scope at less than $400 is a steal.

[mtdoc]

So in the end, I'm thinking the awesome-price Rigol DS1054Z as my go-to scope, plus the Analog Discovery device for the occasional signal generation and logic analyzer. What do you think?

That's a great combination for a budget hobbyist lab.

[nbritton]

The Analog Discovery is a steal if you can get it at the academic pricing. For students they throw in a $65 Analog Parts Kit for free, and for $10 they will also bundle a copy of MultiSim Student Edition. That's $384 worth of gear for $169.

You don't need to be enrolled in a class to get the academic pricing, all you need is an academic email address... what Digilent told me verbatim is: "If there is no specific class requiring this purchase, you can just put "none" in the academic verification field that asks for it."

[nbritton]

For 99% of the time, a 100MHz scope (hacked Rigol 1054Z) and a simple logic analyzer such as Analog Discovery will work just fine.

The truth is you might be able to get by with 100 MHz, but the problem is your measurements won't be accurate. You have to remember that a bandwidth specification is measured to -3dB, so by the time you get to 100 MHz your signal amplitude is already 30% off. Another thing you need to remember is that a square wave is the infinite fourier series summation of the fundamental frequency and all of its odd harmonics, so this means to accurately display a square wave on your screen, from a pragmatic standpoint, you need to capture at least the 3rd, 5th, and 7th harmonics. Furthermore, you'll be aliasing harmonics above the sampling rate, which could possibly give you a false impression. Thus in theory a 100 MHz scope is only accurate up to about 10 MHz on square waves.

[Fungus]

I know that many online comments seem to indicate that USB oscilloscopes should be avoided.

They are correct.

Main reasons:
a) A mouse is the wrong interface for an oscilloscope (how many musicians play on-screen instruments with a mouse?)
b) Requiring a PC always on your workbench is a pain in the ass
c) The supplied software will be awful. Good software costs a lot of money to write, cost-cutting 'scopes don't have it.

You can get them with good software and that don't cut corners with the electronics, but... they cost more than a DS1054Z and you're still stuck with point (a).

Saleae. Seems cool. American made.

And ... useless as an oscilloscope. It doesn't even have a real time view mode to see what you're looking at.

Rigol DS1054Z (DS1074Z Plus?) http://www.rigol.com/prodserv/250/

Winner!

PS: Ignore the "A scope is useless without at least 1GHz bandwith!" and "analogue scopes were good enough for my father, they're good enough for you!" crowd.

So in the end, I'm thinking the awesome-price Rigol DS1054Z as my go-to scope, plus the Analog Discovery device for the occasional signal generation and logic analyzer. What do you think?

Analog Discovery is a great gadget for experimenting and learning stuff.

[CustomEngineerer]

what I would recommend for you is the Rigol MSO2072A, right now this scope is selling for $929.25 over at www.tequipment.net with a special 25% off code.

Thanks for this suggestion. After your comment, I looked very seriously at one of the higher-end Rigols. I'm not sure I want to spend that much, not to mention Dave has a compelling argument to not get the MSO:

If you don't have a signal generator the MSO2072A-S might be a better option for you.

This was another great suggestion. The signal generator I have (one-of-a-kind, that I custom built years ago and packed away in the garage), is probably not a great piece of equipment in today's world. So I looked really hard at the Rigol's with the built in signal generator and/or the MSO feature.

The general consensus seems to be avoiding the higher end Rigol gear (specifically DS4000 & DS6000). I don't have experience with them so can't say for sure, but they seem to be consider a buggy toy for the money you have to spend on them. The DS1000Z & DS2000A series scopes seem to be so popular is because they are decent hardware (for the price), easily hackable, and cheap. While the DS1000Z & DS2000A are just as buggy as the DS4000 ($2300 - $6500) & DS6000 ($5900 - $9600) because don't cost near as much, $300 - $1000 the bugs don't seem to be as big of a deal.

I also wouldn't recommend getting the Rigol builtin signal generator unless you don't have the space for a standalone unit. I bought the DS2072A-S with the builtin signal generator and have regretted not putting the extra $300 it cost towards a decent standalone AWG. The interface is clunky to use while also trying use the oscilloscope to measure a signal. The specs aren't that great, it doesn't do sweeps and its annoying to have to plug into the generator connectors on the back of the scope. While it is probably better than an older home built generator, considering what you can get for around the same price it just isn't worth it except for very specific use cases (no bench space, need all-in-one portable unit, probably a few others). Don't get me wrong, I really do enjoy the DS2072A scope, just not the builtin signal generator.

Edited to remove link to Dave's MSO video

[nbritton]

I've used both 1Gsps 100MHz owon sds7102 and 1Gsps 100MHz owon vds3102 for years, and they have no problems probing 20MHz SPI data bus at all.

Right, because most of the time digital is only concerned with the signal being high or low, any low bandwidth scope can do that. However, to really see exactly what your circuit is doing you need a higher bandwidth scope.

[tautech]

I also wouldn't recommend getting the Rigol builtin signal generator unless you don't have the space for a standalone unit. I bought the DS2072A-S with the builtin signal generator and have regretted not putting the extra $300 it cost towards a decent standalone AWG. The interface is clunky to use while also trying use the oscilloscope to measure a signal. The specs aren't that great, it doesn't do sweeps and its annoying to have to plug into the generator connectors on the back of the scope. While it is probably better than an older home built generator, considering what you can get for around the same price it just isn't worth it except for very specific use cases (no bench space, need all-in-one portable unit, probably a few others). Don't get me wrong, I really do enjoy the DS2072A scope, just not the builtin signal generator.

Would you have a different view if the AWG BNC was on the front panel?

[nbritton]

The general consensus seems to be avoiding the higher end Rigol gear (specifically DS4000 & DS6000). I don't have experience with them so can't say for sure, but they seem to be consider a buggy toy for the money you have to spend on them. The DS1000Z & DS2000A series scopes seem to be so popular is because they are decent hardware (for the price), easily hackable, and cheap. While the DS1000Z & DS2000A are just as buggy as the DS4000 ($2300 - $6500) & DS6000 ($5900 - $9600) because don't cost near as much, $300 - $1000 the bugs don't seem to be as big of a deal.

I agree with that. It's not that the higher end Rigols are worse, it's just that people pay more for them so they expect more from them. I myself am worried that my new DS4000 won't meet my expectations, because for me $2594 is a lot of money. The annuitization for this scope is $22 a month for the next ten years, so for that price it better deliver.

I also wouldn't recommend getting the Rigol builtin signal generator unless you don't have the space for a standalone unit. I bought the DS2072A-S with the builtin signal generator and have regretted not putting the extra $300 it cost towards a decent standalone AWG. The interface is clunky to use while also trying use the oscilloscope to measure a signal. The specs aren't that great, it doesn't do sweeps and its annoying to have to plug into the generator connectors on the back of the scope. While it is probably better than an older home built generator, considering what you can get for around the same price it just isn't worth it except for very specific use cases (no bench space, need all-in-one portable unit, probably a few others). Don't get me wrong, I really do enjoy the DS2072A scope, just not the builtin signal generator.

I totally agree with this, the built-in signal generator is mediocre at best when compared to stand alone AWGs. You would be better off taking the money you would spend for a -S model and putting that, plus a little extra money, towards a Siglent SDG2042X. It pains me to say that because I don't like Siglent gear on a matter of principle because they produce really shitty software, but in terms of price/performance I think the SDG2000X is going to be the new benchmark to beat.

[nbritton]

The entire test apparatus was set based on an Analog Discovery and through hole resistors, no EMI care was taken at all.

The Analog Discovery is not a 5 MHz scope, the reality is its frond end is capable of upwards of 50 MHz @ -3dB. In practice though its 125 MSa/s sampling rate limits it's usable bandwidth to 25 MHz. It basically says this in page 16 of its technical reference manual:

For both scales and both channels, the 0.5dB bandwidth is 10MHz (5MHz@0.1dB).
You can see from the plots, that this circuit exceeded the requirements for 5MHz of bandwidth, and the -3dB point is more than 20MHz. However, since many students who will be using the Analog Discovery don’t understand the concept of “-3dB” is the “bandwidth” of an instrument, and that a 1V input signal with -3dB applied will measure 0.707V, it was felt from a marketing standpoint to specify the bandwidth of the analog inputs as less than -0.5dB as the “bandwidth”. This ensures that when connecting a 10MHz signal on a traditional instrument (with much higher bandwidth), and the Analog Discovery, the measurements will be very similar, and lead to less confusion.

https://www.digilentinc.com/Data/Products/ANALOG-DISCOVERY/Discovery_TRM_RevB_1.pdf

[CustomEngineerer]

I also wouldn't recommend getting the Rigol builtin signal generator unless you don't have the space for a standalone unit. I bought the DS2072A-S with the builtin signal generator and have regretted not putting the extra $300 it cost towards a decent standalone AWG. The interface is clunky to use while also trying use the oscilloscope to measure a signal. The specs aren't that great, it doesn't do sweeps and its annoying to have to plug into the generator connectors on the back of the scope. While it is probably better than an older home built generator, considering what you can get for around the same price it just isn't worth it except for very specific use cases (no bench space, need all-in-one portable unit, probably a few others). Don't get me wrong, I really do enjoy the DS2072A scope, just not the builtin signal generator.

Would you have a different view if the AWG BNC was on the front panel?

No, its an annoyance having the connectors on the back but I have worked around it. My biggest problem with the builtin is that for around the same price I could have gotten a decent bench AWG, followed closely by how annoying it is to try and adjust the generated signal while also trying to capture the signal. I also have needed a sweep function a couple of times recently that pretty much all the bench units around that price seem to have. I have been looking at standalone AWG's recently mainly because of this and have come pretty close to pulling the trigger on one a couple of times. Honestly if Rigol just added a sweep signal (linear and logarithmic) I probably wouldn't be looking for a standalone for now (still wouldn't crazy about the builtin, but would probably be good enough for what I need). Though not even sure if thats something that could be done in a firmware upgrade anyways, so not like I am expecting it.

[CustomEngineerer]

The general consensus seems to be avoiding the higher end Rigol gear (specifically DS4000 & DS6000). I don't have experience with them so can't say for sure, but they seem to be consider a buggy toy for the money you have to spend on them. The DS1000Z & DS2000A series scopes seem to be so popular is because they are decent hardware (for the price), easily hackable, and cheap. While the DS1000Z & DS2000A are just as buggy as the DS4000 ($2300 - $6500) & DS6000 ($5900 - $9600) because don't cost near as much, $300 - $1000 the bugs don't seem to be as big of a deal.

I agree with that. It's not that the higher end Rigols are worse, it's just that people pay more for them so they expect more from them. I myself am worried that my new DS4000 won't meet my expectations, because for me $2594 is a lot of money. The annuitization for this scope is $22 a month for the next ten years, so for that price it better fucking deliver.

Agreed. When I was looking at the DS2072A, I really tried my best to justify the cost of the DS4000 because I really wanted the 4 channels. Kind of funny, the main thing that kept me from doing it was the extra $300 for the extra 2 channels. Then I go and end up spending the extra $300 for the sig gen in the DS2072A-S. This was a little before the DS1000Z's came out or I probably would have gone that route, but I am glad that I got the 2072.

I also wouldn't recommend getting the Rigol builtin signal generator unless you don't have the space for a standalone unit. I bought the DS2072A-S with the builtin signal generator and have regretted not putting the extra $300 it cost towards a decent standalone AWG. The interface is clunky to use while also trying use the oscilloscope to measure a signal. The specs aren't that great, it doesn't do sweeps and its annoying to have to plug into the generator connectors on the back of the scope. While it is probably better than an older home built generator, considering what you can get for around the same price it just isn't worth it except for very specific use cases (no bench space, need all-in-one portable unit, probably a few others). Don't get me wrong, I really do enjoy the DS2072A scope, just not the builtin signal generator.

I totally agree with this, the built-in signal generator is mediocre at best when compared to stand alone AWGs. You would be better off taking the money you would spend for a -S model and putting that, plus a little extra money, towards a Siglent SDG2042X. It pains me to say that because I don't like Siglent gear on a matter of principle because they produce really shitty software, but in terms of price/performance I think the SDG2000X is going to be the new benchmark to beat.

I feel the same way as long as Siglent doesn't totally screw up the firmware (which seems to be a fairly good possibility that they will).

[nbritton]

The entire test apparatus was set based on an Analog Discovery and through hole resistors, no EMI care was taken at all.

The Analog Discovery is not a 5 MHz scope, the reality is its frond end is capable of upwards of 50 MHz @ -3dB. In practice though its 125 MSa/s sampling rate limits it's usable bandwidth to 25 MHz. It basically says this in page 16 of its technical reference manual:

For both scales and both channels, the 0.5dB bandwidth is 10MHz (5MHz@0.1dB).
You can see from the plots, that this circuit exceeded the requirements for 5MHz of bandwidth, and the -3dB point is more than 20MHz. However, since many students who will be using the Analog Discovery don’t understand the concept of “-3dB” is the “bandwidth” of an instrument, and that a 1V input signal with -3dB applied will measure 0.707V, it was felt from a marketing standpoint to specify the bandwidth of the analog inputs as less than -0.5dB as the “bandwidth”. This ensures that when connecting a 10MHz signal on a traditional instrument (with much higher bandwidth), and the Analog Discovery, the measurements will be very similar, and lead to less confusion.

https://www.digilentinc.com/Data/Products/ANALOG-DISCOVERY/Discovery_TRM_RevB_1.pdf

So I tested OWON VDS3102L with absolute shittiest front end, let's scale up the frequency, 20MHz square wave at 100MHZ BW, 1Gsps. Still, no signal integrity care at all.

Duty cycle is 40% because Analog Discovery won't do 50% at 20MHz. BTW, to decrease system BW, I used a non branded 60MHz passive x10 probe.

Added: Colin, the chip whisperer guy, made a video on a 350MHz PicoScope measuring 1GHz at 5Gsps. https://www.youtube.com/watch?v=xIj8W1_xG-s.

That square wave looks piss poor in my opinion. The edges are all rounded because at 20 MHz the OWON, or the Analog Discovery, isn't able to fully display/capture the 7th harmonic. Do a 3 MHz signal from the Analog Discovery and measure it on you best scope.

[Howardlong]

So in the end, I'm thinking the awesome-price Rigol DS1054Z as my go-to scope, plus the Analog Discovery device for the occasional signal generation and logic analyzer. What do you think?

That's a great combination for a budget hobbyist lab.

Totally agreed. While the AD has its limitations, it is a sound piece of test gear in its own right and will cover off your AWG requirement and most LA requirements you might have. The limitation of the LA is mostly down to limited memory and to a lesser extent it only has basic triggering options and the sample rate is limited to 100MSa/s, which may or may not be a problem depending on what you're doing. For the vast majority of hobby stuff, I'd say it's not going to be a problem. The software's pretty good too, nice and responsive and reasonably intuitive.

If you're unable to make the academic pricing, for some reason Microchip Direct has had it priced less than most other outlets in the past, currently $219 vs $279.

Regarding the AWG on the DS1000Z-S, as an AWG for my purposes it ain't half bad, but having the connectors on the back as well as having to battle through the scope menus to get at it isn't perfect. If I used an AWG every day it would drive my nuts. You can do sweeping of sorts setting a channel on FM while modulating it with a triangle but it's not a perfect solution. I ran pigtails from the back to avoid having to access the rear of the scope all the time. I found that it's a compromise at the end of the day, but mostly about usability than functionality.

[CustomEngineerer]

Regarding the AWG on the DS1000Z-S, as an AWG for my purposes it ain't half bad, but having the connectors on the back as well as having to battle through the scope menus to get at it isn't perfect. If I used an AWG every day it would drive my nuts. You can do sweeping of sorts setting a channel on FM while modulating it with a triangle but it's not a perfect solution. I ran pigtails from the back to avoid having to access the rear of the scope all the time. I found that it's a compromise at the end of the day, but mostly about usability than functionality.

Would you mind giving a little more detail on how you fake the sweeping? Sounds like it could be useful in a pinch.

I also did something similar for the generator connectors to avoid having to reach back behind the scope to hook up. I've got the scope a couple of shelves up on my work desk and mounted some bnc chassis mount feed through adaptors at project level on my desk. I keep the 2 generator connectors hooked to those so when I need the generator I can just connect to the ones on the desk. At first I was a little worried that the extra cable length and going through an extra terminal might affect the signal but I have tested it and haven't noticed any problems.

[Howardlong]

I don't know if the DS2000 is the same as the DS1000Z, but try this...

o 1MHz sine
o set the modulation to FM
o modulating frequency 1kHz
o modulate with triangle
o deviation 1MHz

[Wuerstchenhund]

For your aliasing theory, it is absolutely right, so when trying to probe very fast signals, do not use a low sample rate scope. But it has nothing to do with BW, it's only a matter of sampling rate.

I'm sorry but that's nonsense, BW is as much as important as sample rate.

Here's are some screenshots for a quick test done with a 15MHz pulse (50% DC, generated by an Agilent 33522B) probed by a 3GHz 20GSa/s scope (LeCroy WavePro 7300A):

Sampled at full bandwidth with 20GSa/s:




Sampled at 200MHz bandwidth with 20GSa/s:




Sampled at 20MHz bandwidth with 20GSa/s:




It's pretty obvious that the 20MHz shot doesn't resemble the original signal, which is understandable since important frequency components of the original signal are left out, and that even a very high sample rate can't overcome the limitations imposed by a too low analog bandwidth.

Now, just for fun, let's see what impact the sample rate has:

Sampled at 200GS/s (RIS, something like ETS):




Sampled at 20GS/s:




Sampled at 10GS/s:




Sampled at 5GS/s:




Sampled at 2.5GS/s:




Sampled at 1GS/s:




Sampled at 500MS/s:




Sampled at 250MS/s:




Sampled at 100MS/s:




Sampled at 50MS/s:




We can see that the waveform remains valid all the way down to 250MS/s, which considering that the bandwidth necessary for capturing all relevent components of a 15MHz square wave is 120-150MHz, is logical:




So in short, yes, BW does matter, and no, high sample rates are no substitute for bandwidth.

I've used both 1Gsps 100MHz owon sds7102 and 1Gsps 100MHz owon vds3102 for years, and they have no problems probing 20MHz SPI data bus at all.

You've seen something which may or may not resemble what the original signal looks like, and it may even have worked for you, who knows, but that doesn't mean a 100MHz scope will show you all relevant components of a 20MHz pulse.

So I tested OWON VDS3102L with absolute shittiest front end, let's scale up the frequency, 20MHz square wave at 100MHZ BW, 1Gsps. Still, no signal integrity care at all.

I agree with nbritton, that's a really piss-poor waveform, and unless your signal generator actually produces such crap signals then what you see on the scope is completely useless to assess any of the relevant signal parameters. You can get similarly valid results by reading from fish guts.

[Fungus]

I'm sorry but that's nonsense, BW is as much as important as sample rate.

The two should match. If there's a serious mismatch then that's a red flag. You have to wonder who designed the device.

[Fungus]

since many students who will be using the Analog Discovery don’t understand the concept of “-3dB” is the “bandwidth” of an instrument, and that a 1V input signal with -3dB applied will measure 0.707V, it was felt from a marketing standpoint to specify the bandwidth of the analog inputs as less than -0.5dB as the “bandwidth”. This ensures that when connecting a 10MHz signal on a traditional instrument (with much higher bandwidth), and the Analog Discovery, the measurements will be very similar, and lead to less confusion.

Is the the first ever sighting of a manufacturer underselling the bandwidth? 

[Wuerstchenhund]

I'm sorry but that's nonsense, BW is as much as important as sample rate.

The two should match. If there's a serious mismatch then that's a red flag. You have to wonder who designed the device.

Exactly. A chain is only as good as its weakest link.

[nbritton]

Attached are some screenshots from my Analog Discovery measuring a 5V 1 MHz, 3 MHz, and 10 MHz square waves.

[mtdoc]

Attached are some screenshots from my Analog Discovery measuring a 5V 1 MHz, 3 MHz, and 10 MHz square waves.

Are you using the AD's AWG to produce the square wave?. If so, try a different signal source.

[Rupunzell]

20 Mhz @ 10mV square wave from a Tek 2102 pulse generator (circa late 1960's). Display using a Tek 7104, 7A29, 7B10 = 1Ghz real time.

Note the signal fidelity, low noise and wave form fidelity and image quality.

Gaussian response, no input filter worries, no worries about sampling rate issues, No fiddling with touch screens and menus, concerns about issues directly related to analog to digital conversion are gone as there is no analog to digital conversion. Just direct, accurate real time response and display of the input signal.

While DSO-MSO have their place in the test and measurement world, there is also a place for high quality CRT based time domain instruments.





Bernice

[Fungus]

Note the signal fidelity, low noise and wave form fidelity and image quality.

It's an illusion...

[Fungus]

Attached are some screenshots from my Analog Discovery measuring a 5V 1 MHz, 3 MHz, and 10 MHz square waves.

I don't own an AD but I would have expected slightly better than that...

The thing that makes it look really ugly is that it's not using sin(x)/x interpolation in the display. Is there any way to turn that on in the software?

[nbritton]

Attached are some screenshots from my Analog Discovery measuring a 5V 1 MHz, 3 MHz, and 10 MHz square waves.

I don't own an AD but I would have expected slightly better than that...

The thing that makes it look really ugly is that it's not using sin(x)/x interpolation in the display. Is there any way to turn that on in the software?

Well three things to realize, first the AD is an educational tool, second running both the AD's AWG and DSO eats up double? the sample rate, and thirdly I ran the test wrong, the default square wave on my AD's AWG is from +5V to -5V... I should have changed the DC offset.

[gojimmypi]

For your aliasing theory, it is absolutely right, so when trying to probe very fast signals, do not use a low sample rate scope. But it has nothing to do with BW, it's only a matter of sampling rate.

I'm sorry but that's nonsense, BW is as much as important as sample rate.

Here's are some screenshots for a quick test done with a 15MHz pulse (50% DC, generated by an Agilent 33522B) probed by a 3GHz 20GSa/s scope (LeCroy WavePro 7300A):

Thanks for spending the time to post that information & screen snips!

[alsetalokin4017]

Can I play too?

Scope: Rigol DS1054Z "unlocked" to 100MHz bw
Signal source: DataPulse (Systron Donner) DP-101
Connection: 2 lousy 50-ohm BNC patchcords spliced together with double-female, with Rigol 50-ohm thru-terminator at scope end

[gojimmypi]

Ok, I've spent hours on this (Dave has some really awesome video reviews!)... and I plan to order from amazon today (really can't beat the prime shipping, return poliucy, and 3% cash back on amazon/chase card)

So for others still researching and reading, I'm including some additional information:

First the Rigol page:

http://www.rigolcanada.com/products/digital-oscilloscopes/ds1000Z/ds1054z/

And Dave's feature list video:


Dave really expresses his opinion of the DS1054z at Time Index 31:30
https://youtu.be/W2qdtQkBKhc?t=1898

I had considered the other scopes below, however each had drawbacks: all are only 2 channel with limited storage depth. Hard to beat the Rigol 4 channels at 24meg max (6 meg when using all 4 channels)

Siglent SDS1102CML Digital Storage Oscilloscope, 100MHz, 7" TFT-LCD Display
http://www.amazon.com/gp/product/B00GQNNL1U

B&K Precision 2190D Digital Storage Oscilloscope, 1 GSa/s, 100 MHz Bandwidth
http://www.amazon.com/gp/product/B00SS0A0JU

Owon SDS7102 Deep Memory Digital Storage Oscilloscope 2-channel with VGA and LAN interface
http://www.amazon.com/gp/product/B006G54K3G

Tektronix TBS1052B-EDU 50 MHz, 2 Digital Channel Oscilloscope, 1 GS/s Sampling
http://www.amazon.com/gp/product/B00KAKI58Y

(I admit it was hard not to go with the usual gold-standard in oscilloscopes: Tektronix)

The 2232 mentioned in a prior post, although old, does have impressive specs: Sample Rate - 100 MS/s per channel. Effective sample rates up to 2 GS/s in repetitive storage mode (0.5 µs/div and faster in single-channel mode, 0.2 µs/div and faster dual-channel).

(it must have been expensive in its day). But not a lot of storage: Record Length - 4K or 1K selectable. 2K or 512 per channel in dual channel mode.

http://www.tek.com/datasheet/2232-digital-and-analog-oscillscope

There's also apparently some interesting software available (Thanks Dave, for including this in the video!), that can talk to the DS1054z via Ethernet LXI
https://www.eevblog.com/forum/testgear/free-ds1052eds1102e-software-for-linux/msg690621/#msg690621

In particular the stuff posted by marmad looks potentially very useful, if it works with the new DS1054z:
https://www.eevblog.com/forum/projects/software-tips-and-tricks-for-rigol-ds200040006000-ultravision-dsos/

I use this software to control the scope, view live waveforms and download screenshots or memory waveform data.
No need to install 1GB of bloatware (visa, rigol). Works fine for me.

http://www.teuniz.net/DSRemote/

Latest version supports LAN & USB.

Here's a link to the DSRemote open source linux software:

https://github.com/Teuniz/DSRemote

(I'm ever more excited to order my DS1054z now!)

From Dave's video, it seems the Rigol software is really dreadful. Not a showstopper, but could have made this an even more awesome product.

If I were to add a killer feature: an HDMI screen output would make the Rigol a ridilously cool scope.

Thanks everyone for the really great input! 

[Fungus]

Well three things to realize, first the AD is an educational tool

Yes, I'm not expecting greatness...

I ran the test wrong

Yep. That's more like I'd expect to see for that bandwidth and no sin(x)/(x) display.

[alsetalokin4017]

@Bernice...

Gotta love the 7104!   

"A one GHz _analog_ scope was good enough for my daddy..... "   

[Fungus]

From Dave's video, it seems the Rigol software is really dreadful. Not a showstopper, but could have made this an even more awesome product.

Rigol's remote control software? Yes, it's pretty bad. I guess you can't have everything for $400. 

I don't have any real reason to use it though. If I need a screenshot I just put a USB stick in the front connector and press the 'print' button.

If I were to add a killer feature: an HDMI screen output would make the Rigol a ridilously cool scope.

Also: 8 inputs, 1GHz bandwidth and a signal generator(!) 

[alsetalokin4017]

@gojimmypi:

Please allow me to recommend TEquipment as your USA vendor for the DS1054z. You really _can_ beat Amazon, I think. (Someone will send you the EEVblog TEquipment discount code if you ask for it....)

ETA: Two things: I had to return my original DS1054z under the TEquipment warranty (bad glitch on one channel) and had a replacement in hand in less than a week. And I just took delivery of an Extech LT300 light meter that someone else ordered for me from Amazon... and it arrived with a previously-opened and resealed box, a completely dead battery, and a clumsily reattached screenprotector film..... but it was sold as new.

[tautech]

Ok, I've spent hours on this ... and I plan to order from amazon today (really can't beat the prime shipping, return poliucy, and 3% cash back on amazon/chase card)


Siglent SDS1102CML Digital Storage Oscilloscope, 100MHz, 7" TFT-LCD Display
http://www.amazon.com/gp/product/B00GQNNL1U

B&K Precision 2190D Digital Storage Oscilloscope, 1 GSa/s, 100 MHz Bandwidth
http://www.amazon.com/gp/product/B00SS0A0JU

FYI
The B&K is a re-branded Siglent.

[Mosaic]

Regarding the issue of SPI requiring additional inputs to decode on a DS2000 series scope.
Technically true but practically not essential it seems as often one of the channels is occupied by dummy bytes:
http://www.bitwizard.nl/wiki/index.php/SPI_versus_I2C_protocols

[mtdoc]

Attached are some screenshots from my Analog Discovery measuring a 5V 1 MHz, 3 MHz, and 10 MHz square waves.

I don't own an AD but I would have expected slightly better than that...

The thing that makes it look really ugly is that it's not using sin(x)/x interpolation in the display. Is there any way to turn that on in the software?

Well three things to realize, first the AD is an educational tool, second running both the AD's AWG and DSO eats up double? the sample rate, and thirdly I ran the test wrong, the default square wave on my AD's AWG is from +5V to -5V... I should have changed the DC offset.

Well, you peaked my curiosity - so here is my AD generating and simultaneously recording a 10 MHz square wave (I had forgotten the AWG could do that high of frequency!) and for reference, the same signal fed into my 200 MHz bandwidth Rigol.

I'd say the AD does pretty darn well all things considered.

[Fungus]

I'd say the AD does pretty darn well all things considered.

Yep.

[gojimmypi]

another somewhat related question: is there any reason to have the 50 ohm adapter for a scope being used on relatively low frequencies (<100MHz) ?  what specific circumstances require a 50 ohm adapter?

[tggzzz]

another somewhat related question: is there any reason to have the 50 ohm adapter for a scope being used on relatively low frequencies (<100MHz) ?  what specific circumstances require a 50 ohm adapter?

99MHz is not "relaively low frequency". A 15pF scope probe with a 6 inch ground lead will resonate and ring at ~100MHz.

If you have a "low impedance Z0 probe" (which has a higher impedance than a so-called "high impeadance probe", the you will need a  50ohm termination.

FFI, see https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/

[nctnico]

another somewhat related question: is there any reason to have the 50 ohm adapter for a scope being used on relatively low frequencies (<100MHz) ?  what specific circumstances require a 50 ohm adapter?

It all depends on your frequency and cable length, say, for 30MHz, the wavelength in free air is 10M. Assuming you are using RG316 test cable, then the effective wavelength is 7M.

As a rule of thumb, 1/10 wavelength and longer cable calls for attention on signal integrity, so as long as your cable is longer than 2ft, you will need to terminate it properly.

There are some BNC terminators on eBay, rated up to many gigahertz. For SMA connector you will have more choices. They generally cost <$10 for a used branded or a new unbranded.

Yes and no. The real problem in this case is the input capacitance of high-Z (standard) probes and 1M Ohm oscilloscope inputs. As a rule of thumb: that input capacitance kills any chance of measuring signals (containing harmonics) over 100MHz correctly.
Even when using a 50 Ohm terminator parallel to tens of pf isn't going to work right so using a (feed-through) terminator isn't going to help at very high frequencies. This is why you'll find 50 Ohm inputs on any decent oscilloscope having a bandwidth over 150MHz.

[gojimmypi]

thanks for the replies!

Say I had a hi-z scope (the DS1054)... and a 50 ohm coax cable signal that I wanted to measure....

Would I be able to plug the high-z probe into a coax "T" with one side terminated with a 50 ohm terminator, and the other receiving the 50 ohm signal - and get a proper measurement?

[gojimmypi]

for anyone looking for a hobbyist scope, I found this pdf file while googling for "50 ohm" stuff... lab notes from a 2007 UC Berkeley Class:

Function Generator and Oscilloscope - In this lab you learn how to use the oscilloscope and function generator
https://inst.eecs.berkeley.edu/~ee100/su07/lab/lab2-FunctionGeneratorOscilloscope/eecs100_eecs43_lab2-fncn_generator_scope.pdf

perhaps someone might find it useful

[TheSteve]

thanks for the replies!

Say I had a hi-z scope (the DS1054)... and a 50 ohm coax cable signal that I wanted to measure....

Would I be able to plug the high-z probe into a coax "T" with one side terminated with a 50 ohm terminator, and the other receiving the 50 ohm signal - and get a proper measurement?

Depends on the frequency - if it isn't too high this may be fine depending on what you want to do.

Can you give us a more detailed example?

[gojimmypi]

thanks for the replies!

Say I had a hi-z scope (the DS1054)... and a 50 ohm coax cable signal that I wanted to measure....

Would I be able to plug the high-z probe into a coax "T" with one side terminated with a 50 ohm terminator, and the other receiving the 50 ohm signal - and get a proper measurement?

Depends on the frequency - if it isn't too high this may be fine depending on what you want to do.

Can you give us a more detailed example?

Say a 50 ohm terminator like this: http://www.amazon.com/gp/product/B00G10MKCO

and a "T" like this: http://www.amazon.com/dp/B0000510YX/

plug the male end of the T into the scope, put the terminator on one of the female connectors of the T, and use a Hi-Z scope on the other female connector of the T.

as I talk through this, I think this is actually a silly idea, no? The scope will be an unterminated part of the transmission line causing problems.  (it has been a long time since my EE classes. did I mention I work as a software engineer these days?) 

[gojimmypi]

Added: https://www.youtube.com/watch?v=OiAmER1OJh4.

Another Dave video! Awesome. thanks

I also came across this National Instruments white paper "Select the Correct Oscilloscope Probe for Your Application":

http://www.ni.com/white-paper/14825/en/

edit: as internet links sometimes change, I've attached the NI Whitepaper

[alsetalokin4017]

another somewhat related question: is there any reason to have the 50 ohm adapter for a scope being used on relatively low frequencies (<100MHz) ?  what specific circumstances require a 50 ohm adapter?

I see you've gotten all kinds of theoretical answers to your question. Here is an actual test case. I already posted the scopeshot _with_  the 50 ohm thru-terminator up above, but I'll put another one here. The specific circumstance in this case is when you are scoping something with an output impedance of 50 ohms -- like most signal/function generators --, and with a cable connection of 50 ohm impedance.

Scope: Rigol DS1054z, unlocked to 100 MHz bw.
Signal source: DataPulse (Systron Donner) DP-101, output impedance 50 ohms, set to produce a 5 V (by knob markings) positive going square pulse train at 10 MHz.
Connection: 50 ohm coax BNC patchcords RG-58/U, two pieces "spliced" with a double-female BNC, total length about 6 feet.
Terminator: Rigol 50-ohm thru-terminator (aka impedance adapter), 18 dollars from TEquipment:
http://assets.tequipment.net/assets/1/26/DimRegular/Adaptor2.JPG

First shot below is with terminator at the scope channel input. Second shot is without the terminator, using the _exact same_ settings on the pulse generator.

Moral: You pays your money, and you takes your chances.

[alsetalokin4017]

And just for the sake of completeness, here's a shot using a BNC T connector and a 50 ohm end-terminator at the scope, as suggested above.
(ETA: But _not_ using a high-z probe (which would indeed be silly) , rather using the same BNC patch cable connection as my above shots.)

[gojimmypi]

another somewhat related question: is there any reason to have the 50 ohm adapter for a scope being used on relatively low frequencies (<100MHz) ?  what specific circumstances require a 50 ohm adapter?

I see you've gotten all kinds of theoretical answers to your question. Here is an actual test case. ....

That's great info, thanks for taking the time to post it.

In this case, you knew your signal source was 50 ohms. When poking around in a random circuit board, I assume the high impedance setting is preferred? Do you have an example of a circuit-analysis situation where there's not an obvious 50 ohm BNC connector.... where one would need an impedance adapter?

thanks again for your responses.

cheers

[alsetalokin4017]

another somewhat related question: is there any reason to have the 50 ohm adapter for a scope being used on relatively low frequencies (<100MHz) ?  what specific circumstances require a 50 ohm adapter?

I see you've gotten all kinds of theoretical answers to your question. Here is an actual test case. ....

That's great info, thanks for taking the time to post it.

In this case, you knew your signal source was 50 ohms. When poking around in a random circuit board, I assume the high impedance setting is preferred? Do you have an example of a circuit-analysis situation where there's not an obvious 50 ohm BNC connector.... where one would need an impedance adapter?

thanks again for your responses.

cheers

You are welcome. Yes, in most cases with low frequency signals -- defined by me as being 10 MHz and under -- one would normally use the standard 10x attenuated passive probe and the 1Megohm scope input impedance, as this setup will load the circuit under test the least. In most cases. This is probably why the Rigol designers didn't put a selectable 50ohm-1Megohm input impedance on their low-bandwidth scopes.

I'm not an EE (although I sometimes pretend to be one on YouTube, hah) but I'm sure that there are more qualified people here who can answer your question better when higher frequencies, active probes, and better scopes are concerned.

I will caution you with another quote from my favorite physicist, though...
"It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong."
--Richard Feynman

Bottom line: Get the Rigol 1054z, unlock it to 100 MHz bandwidth, and also order the 50 ohm adapter-terminator of your choice, and use it when you are patching directly to your FG, or whenever you think it may be appropriate.

[alsetalokin4017]

And even more completeness:

First shot below is the PG's output, scoped with the stock Rigol probe, 10x setting, connected to the PG's BNC output jack, no other termination.

Second shot is the "silly" connection: the probe connected to the PG as above and connected to the scope with a "T" and 50 ohm end-terminator. Blecch fooey.

Of course the PG's settings have not changed in this whole test series.

[Howardlong]

You'll also find the response will change depending on the length of 50 ohm coax from your AWG to the 10X 10M ohm probe point due to the reflections incurred.

Another test you could do is to run an arbitrary length of 50 ohm coax from the AWG, use a 50 ohm thru terminator (or T piece plus terminator) at the other end of the coax from the AWG, and probe with the 10X 10M ohm probe at the thru terminator. The result should be pretty similar to probing with the 10X probe directly at the AWG with the thru terminator.

[TheSteve]

Hah - I thought he meant to use the T connector so he could have the load terminated properly and have a port to connect the tip end of the probe in to.  Which is totally fine until the frequency gets too high. Obviously connecting the BNC end of the probe into the T is just a bad idea all around.

[CustomEngineerer]

I don't know if the DS2000 is the same as the DS1000Z, but try this...

o 1MHz sine
o set the modulation to FM
o modulating frequency 1kHz
o modulate with triangle
o deviation 1MHz

Ahh, I see what you mean. That does work on the DS2000, thank you for sharing.

[nbritton]

Added: https://www.youtube.com/watch?v=OiAmER1OJh4.

Another Dave video! Awesome. thanks

I also came across this National Instruments white paper "Select the Correct Oscilloscope Probe for Your Application":

http://www.ni.com/white-paper/14825/en/

edit: as internet links sometimes change, I've attached the NI Whitepaper

[tggzzz]

I'm sorry but that's nonsense, BW is as much as important as sample rate.

The two should match. If there's a serious mismatch then that's a red flag. You have to wonder who designed the device.

Well, 25 years ago I knew the people that designed HP's front ends, and they certainly weren't fools. A 1GHz 40ns-25MS/s (or was it 25ns-40MS/s?) scope was very useful when observing the signal integrity of sub-nanosecond edges.

If you want to consider the maths of sampling real-time signals, don't forget that if you have an AM audio signal on a 100MHz carrier, you only have to digitise it at ~40kS/s to completely reconstruct the signal. Of course the sampler has to have bandwidth >100MHz.

[Wuerstchenhund]

Well, 25 years ago I knew the people that designed HP's front ends, and they certainly weren't fools.

No, they certainly weren't fools, but they had to work with limitations of the technology that was available back then (although 25yrs ago HP already made 1GSa/s scopes), and which no longer exist in 2015.

[G0HZU]

If you want to consider the maths of sampling real-time signals, don't forget that if you have an AM audio signal on a 100MHz carrier, you only have to digitise it at ~40kS/s to completely reconstruct the signal. Of course the sampler has to have bandwidth >100MHz.

Agreed. AFAIK HP had (low sample rate) sampling scopes with 1GHz bandwidth back in 1960.

My old HP vector voltmeter uses similar front end technology and offers 1GHz BW and it dates back to the mid 1960s.

[gojimmypi]

@gojimmypi:

Please allow me to recommend TEquipment as your USA vendor for the DS1054z. You really _can_ beat Amazon, I think. (Someone will send you the EEVblog TEquipment discount code if you ask for it....)

ETA: Two things: I had to return my original DS1054z under the TEquipment warranty (bad glitch on one channel) and had a replacement in hand in less than a week. And I just took delivery of an Extech LT300 light meter that someone else ordered for me from Amazon... and it arrived with a previously-opened and resealed box, a completely dead battery, and a clumsily reattached screenprotector film..... but it was sold as new.

I appreciate the recommendation. I still ended up ordering the DS1054z on amazon, but TEquipment was the seller. I added the scope to the cart from the eevblog page, as it appears Dave gets a percentage of the sale. I recently learned folks can donate to him as well, which I plan to do (this information is usually hidden in the "show more" section on youtube):

Support the EEVblog through Patreon!
http://www.patreon.com/eevblog

Dave is really awesome! I really like the videos and hope he continues to create content.

I did send an email to TEquipment asking about warranty repairs. Here's their response:

Please be advised that with Rigol you have an Exclusive 30-day money back guarantee will allow you to fully test your investment to make sure it works for you. If it does not meet your expectations, give us a call and we'll work out the return or offer a better solution.
In other words, for the first 30 days after you receive your unit, we will administrate the warranty repair or replacement.
After the 30 days, your warranty is with the manufacturer.

And so with amazon, I get the same 30 day deal - but return shipping is free. It is a ridiculously cool system that I've used on occasion. Amazon let's you print a return label online, then just take the box to a UPS store for free returns. (plus there's a UPS store walking distance from my home).

So TEquipment still received my business, just via amazon. I got a 3% cashback from amazon, Dave gets a cut, and I have piece of mind that I don't have to pay expensive shipping costs if I need to return it. Oh, and did I mention it will arrive on Wednesday? 2-day Prime shipping is awesome. Add to this I cut the cable a few years back and amazon Fire TV is the only thing on my screen.  But I regress, this is sounding more like an amazon commercial. 

This has been really crazy. I spent more time shopping for a $400 oscilloscope than I think anything else I've bought in recent memory. lol.  If it had been a Tek, I don't think I would have hesitated so much. My only concern is the tiny size. Again, an HDMI cable on the back would be just fantastic.

I'm really excited to play with my toy! I haven't been this excited since my Heathkit Multimeter package arrived in the mail when I was 14.     (and yes, I still have it!)

Thanks again everyone for their input, particularly since I certainly was not the first one to ask the "which oscilloscope" question.

[Rupunzell]

History of Sampling technology:
http://w140.com/kurt/50_years_sampling.pdf

hp used Ghz sampling technology in more than just the 8405A Vector Volt Meter, hp 3406A sampling RF voltmeter, hp 4851A Vector Impedance meter (study the 4815A probe) and others, circa early 1960's technology.

The video folks were pushing slightly past Nyquist using pulse discriminator and got useable information recovered.

Sampling information systems are not new, GHz sampling systems have been around in instrumentation and systems for over 50 years now. What has changed is the data centric technology world of today putting real world analog conversion to bits of data central to many information systems today.

-Yet most tend to forget the ways of Nature remains analog.


Bernice

If you want to consider the maths of sampling real-time signals, don't forget that if you have an AM audio signal on a 100MHz carrier, you only have to digitise it at ~40kS/s to completely reconstruct the signal. Of course the sampler has to have bandwidth >100MHz.

Agreed. AFAIK HP had (low sample rate) sampling scopes with 1GHz bandwidth back in 1960.

My old HP vector voltmeter uses similar front end technology and offers 1GHz BW and it dates back to the mid 1960s.

[gojimmypi]

I came across this article & thought I'd share for any future readers of this thread regarding the high impedance vs 50 ohm oscilloscope input topic:

"What's Wrong with my Function Generator? (hint: nothing)"
http://www.effectivebits.net/2011/12/whats-wrong-with-my-function-generator.html

[coppice]

Sampling information systems are not new, GHz sampling systems have been around in instrumentation and systems for over 50 years now. What has changed is the data centric technology world of today putting real world analog conversion to bits of data central to many information systems today.

As soon as Shannon formalised the sampling theorem in a way that engineers took notice of (as opposed to the various formulations of the same theorem by various people in maths and statistics many years before) people were busy making the narrowest aperture samplers they could for various jobs. Oscilloscopes were an obvious use.

[tautech]

I came across this article & thought I'd share for any future readers of this thread regarding the high impedance vs 50 ohm oscilloscope input topic:

"What's Wrong with my Function Generator? (hint: nothing)"
http://www.effectivebits.net/2011/12/whats-wrong-with-my-function-generator.html

On a similar topic there is a thread here:
https://www.eevblog.com/forum/testgear/show-us-your-square-wave/

[Wuerstchenhund]

IMHO people still build very low sampling rate and very high BW scopes nowadays. This is the only feasible way to get low cost and very high BW scopes. A good example is PicoScope 9000 series, with 10G BW and only 1M sampling rate.

Yes but these are essentially niche products which come with tons of limitations (plus the general annoyance of being USB scopes), however as you said they are also relatively cheap.

With real time technology there is no way to get such a piece of equipment at only $9000.

No, but then, low cost isn't always a top-most priority, and the benefit of having a capable real-time scope often outweighs the price difference.

At the end of the day it comes down what you want to do and how big your budget is.

[gojimmypi]

Now that my DS1054z is in transit, I realized I forgot to ask as important question: what sort of transient response should I expect from a digital oscilloscope? Will I be able to see switch bounce noise? or if some spike occurs between samples, I'll never know, right? I think I have only ever used an analog scope. But a 100MHz scope should see most transient stuff, right?

[Fungus]

Will I be able to see switch bounce noise?

Yes.

[tggzzz]

Now that my DS1054z is in transit, I realized I forgot to ask as important question: what sort of transient response should I expect from a digital oscilloscope?

Unless you have exotic applications (e.g. photon counting), everything is analogue[1]. Digital circuits merely interpret analogue signals in a quantised fashion - usually but not always binary.

The principal measure of a scope's performance is the bandwidth of its analogue front end measured in Hz, which includes amplifiers, filters and (where appropriate) sampler. The number of samples per second is, to a large extent, a marketing tool.

Yes, I do realise that one of the fundamental limitations on shrinking transistors is that they get too small to contain "enough" electrons at any instant - and so their operation becomes probabilistic.

[gojimmypi]

thanks for the replies on transient response. although the timestamps don't show it, I woke up at 2:00am (!) with a sudden thought of not just reconstructing waveforms, but what happens with the unexpected glitch and how a digital oscilloscope might handle those noise spikes. I ended up finding and reading this article:

Sin(x)/x interpolation: an important aspect of proper oscilloscope measurements
http://www.eetimes.com/document.asp?doc_id=1272526

Well, the new scope should arrive tomorrow... I'm anxiously awaiting a chance to take it for a test drive! I'm interested in any suggestions on tests for proper operation. thanks!

[tautech]

Sin(x)/x interpolation: an important aspect of proper oscilloscope measurements
http://www.eetimes.com/document.asp?doc_id=1272526

It is and it isn't.
With a fast enough sampling rate Dot mode is more accurate.

Well, the new scope should arrive tomorrow... I'm anxiously awaiting a chance to take it for a test drive! I'm interested in any suggestions on tests for proper operation. thanks!

Let's hope you made the right decision. 

See if you can add to this list:
https://www.eevblog.com/forum/testgear/rigol-ds1000z-series-(ds1054z-ds1074z-ds1104z-and-s-models)-bugswish-list/

[alsetalokin4017]

One feature of the 1054z that I really like is the "Pass-Fail" mask function. You can display a waveform, and generate a mask and squeeze it down so that it narrowly bounds the waveform, then "stop on fail" and any glitch that causes the waveform to exceed the boundary of the mask will stop the scope and save the glitch on screen.

For example:

[tautech]

One feature of the 1054z that I really like is the "Pass-Fail" mask function. You can display a waveform, and generate a mask and squeeze it down so that it narrowly bounds the waveform, then "stop on fail" and any glitch that causes the waveform to exceed the boundary of the mask will stop the scope and save the glitch on screen.

The DS1000 series mask performance is quite poor as rf-loop states here:
https://www.eevblog.com/forum/testgear/evaluating-oscilloscopes-for-best-waveform-update-rates/msg737860/#msg737860
BTW, he has one and has tested it.

[alsetalokin4017]

One feature of the 1054z that I really like is the "Pass-Fail" mask function. You can display a waveform, and generate a mask and squeeze it down so that it narrowly bounds the waveform, then "stop on fail" and any glitch that causes the waveform to exceed the boundary of the mask will stop the scope and save the glitch on screen.

The DS1000 series mask performance is quite poor as rf-loop states here:
https://www.eevblog.com/forum/testgear/evaluating-oscilloscopes-for-best-waveform-update-rates/msg737860/#msg737860
BTW, he has one and has tested it.

Well.... since I _want_ the scope to stop when it sees a glitch, I don't see the problem that rf-loop is complaining about. As I show in the video above, it works as I want it to work. YMMV of course.  It's a 400 dollar, low bandwidth scope. What does rf-loop expect for that price and performance level? The Siglent SDS2000 that he compares it to costs more than twice as much and its display doesn't look nearly as nice.

[gojimmypi]

One feature of the 1054z that I really like is the "Pass-Fail" mask function. You can display a waveform...

That's cool; How did you get such a crisp video of your 1054z screen?

[Wuerstchenhund]

Sin(x)/x interpolation: an important aspect of proper oscilloscope measurements
http://www.eetimes.com/document.asp?doc_id=1272526

The article is 6 years old and from a time where cheap entry-level scopes didn't necessarily have sin(x)/x interpolation, but these days I doubt you'll find many that don't have it. Of course the basics discussed are still correct, but it fails to show the limitations of sin(x)/x, as certain conditions need to be met for it to produce a valid waveform.

Here's an (also older but still valid) paper discussing the limitations of interpolation:
http://cdn.teledynelecroy.com/files/whitepapers/wp_interpolation_102203.pdf

[alsetalokin4017]

One feature of the 1054z that I really like is the "Pass-Fail" mask function. You can display a waveform...

That's cool; How did you get such a crisp video of your 1054z screen?

You're kidding, right? My old Panasonic video camera and the various transcoding and compressions used give me a pretty fuzzy video picture, not at all as nice as Dave's videos or others from more modern kit.
Oh... maybe you mean the screenshots toward the end of the video. Those are made by sticking a USB stick in the scope's hole and pressing the "print" button (under the Help button) which saves the screen as a .png (or .jpg) file to the stick. Then I insert the saved images into the video using the OpenShot nonlinear video editor on my Linux computer.

[rf-loop]

One feature of the 1054z that I really like is the "Pass-Fail" mask function. You can display a waveform, and generate a mask and squeeze it down so that it narrowly bounds the waveform, then "stop on fail" and any glitch that causes the waveform to exceed the boundary of the mask will stop the scope and save the glitch on screen.

The DS1000 series mask performance is quite poor as rf-loop states here:
https://www.eevblog.com/forum/testgear/evaluating-oscilloscopes-for-best-waveform-update-rates/msg737860/#msg737860
BTW, he has one and has tested it.

Well.... since I _want_ the scope to stop when it sees a glitch, I don't see the problem that rf-loop is complaining about.

It works ok IF you use it as you told. But, if example want counter for pass and fail you can not trust at all this pass/fail ratio.
This is just as "know your equipment limits" for avoid mistakes.

[nbritton]

I just got my MSO2072A in the mail and the one thing that stands out the most is the 8 inch screen is too small. I have the scope stilling at the back of my desk and the fonts on the screen are so small that you can barely read the words. I have to squint and move in just to decipher what's on the screen. Very annoying, I'd hate to see what it looked like on the DS1054Z because that one only has a 7 inch screen.

Also within just a few hours of use I'm already frustrate that it doesn't have 4 channels.

[Howardlong]

I can sympathise: as a comparison, the 7" on the 1054Z is indeed small: I generally like high density, but this is a little extreme for daily use for me, but an acceptable compromise for portability in the field. The 9" on the MDO3000 I have I find just about perfect for bench use (same resolution as the 1000Z & DS/MSO2000 series at 800x480). At the other end of the scale, the Agilent 7000 I have is a 12" beast at 1024x768 and it's a bit like Duplo in comparison.

As a comparison, for quite some time for my main day to day scope I used up until quite recently an Agilent 54642D 2+16 MSO, even though I had a selection of other 4 channel scopes about, because the UI on those scopes is just so easy to use and responsive. For almost all I did it was fine, but when messing with things like SMPS, I found I missed the extra analogue channels, and I had a 54622D hooked up to the trigger permanently in case I needed it. By the way, the wavefrom display on those scopes is 1000x255 inside a 7" 4:3 CRT, it is always super clear, but there's a lot less unnecessary chrome and other clutter on the screen than the Rigols, but that's what people expect these days.

[Gixy]

I just got my MSO2072A in the mail and the one thing that stands out the most is the 8 inch screen is too small. I have the scope stilling at the back of my desk and the fonts on the screen are so small that you can barely read the words. I have to squint and move in just to decipher what's on the screen. Very annoying, I'd hate to see what it looked like on the DS1054Z because that one only has a 7 inch screen.

Also within just a few hours of use I'm already frustrate that it doesn't have 4 channels.

Hi,
As mentionned elsewhere in this forum, cases where you really need more than 2 analog channels are very rare. Don't forget that you have with your MSO2072A 16 digital channels with which you can observe the digital buses and discrete signals of your circuit.
Having also an MSO2072A (now MSO2302A...), I find only the measurement texts below the traces too small; furthermore, the character font used for those texts is less readable (Times New Roman or equivalent), and looks bad compared to others texts on the screen.
Don't worry, you have made a good choice and will have a lot of fun with this scope!
Denis

[khtwo2002]

I just got my MSO2072A in the mail and the one thing that stands out the most is the 8 inch screen is too small. I have the scope stilling at the back of my desk and the fonts on the screen are so small that you can barely read the words. I have to squint and move in just to decipher what's on the screen. Very annoying, I'd hate to see what it looked like on the DS1054Z because that one only has a 7 inch screen.

Also within just a few hours of use I'm already frustrate that it doesn't have 4 channels.

Dont know if this reading lens could help:
http://www.ebay.com/itm/Pocket-3X-A4-Full-Page-Magnifier-Sheet-Fresnel-Lens-Reading-Map-Magnifying-Loupe-/351293110162?hash=item51cab37792:g:71sAAOSw1vlUwK0e

[khtwo2002]

I just got my MSO2072A in the mail and the one thing that stands out the most is the 8 inch screen is too small. I have the scope stilling at the back of my desk and the fonts on the screen are so small that you can barely read the words. I have to squint and move in just to decipher what's on the screen. Very annoying, I'd hate to see what it looked like on the DS1054Z because that one only has a 7 inch screen.

Also within just a few hours of use I'm already frustrate that it doesn't have 4 channels.

Probably this one shows clearer about the magnifying effect
http://www.ebay.com/itm/XL-Full-Page-Magnifying-Sheet-Fresnel-Lens-3X-Magnification-Magnifier-UF-/161859864168?hash=item25af998668:g:RGkAAOSwl9BWINJO

[ornobian]

In my opinion, Rigol DS1054Z will be the winner of the hobbyist. You will like it.

[Gandalf_Sr]

Yup, you're gonna dig the 1054Z, best $300 I ever spent.