Advice about oscilloscope to buy.

[rf-loop]

I have used  many different oscilloscopes over 45 years. In hobby (or better say hobbies) and in work in industry, with power electronics and for many kind of electronic systems for adjust systems, for repair systems and for test some own designed electronics in industry and also bit in military. There have been industrial analog and digital control systems, including also old  analog computer systems (example EIA, long time ago) what some times need calibrate and so on. In hobby also radio communication systems and some tiny old "computer" systems based with 6800 and 6809 and later some others. Today all is more like playing like kids and some times more seriously.

There have nearly always been availabe 2 and 4  etc channel scopes for use if need. Analogs and later also digitals.

Rough estimate if I think all hours what I ever have used oscilloscope(s) it is not much wrong if I estimate that >>99.5%  1 or 2 channel. <>0.5% 3 - 4 channels and very tiny part from this time even over 4 channels (really rare).  Perhaps so that very old times need was more rare than today.

Nearly all times 100MHz have been minimum. But never needed over 1GHz oscilloscope in my own use.

But also it is perhaps true that if my active time start today with today's electronics, it is possible that 3-4 channel needs have rised. But, I can still think that there is lot of use and users who never really need 3- 4 channels Then there is users who need quite often 3-4 channels.

What is nice to play is not always what we really need.

Finally, equipment do not rise your skills.
I can make lot of miracles with quite simple equipmnets what noob can not do even if he have thousends features scope what price is one expensive car.

We take one failed some old equipment and I take old Tek 2465 and then some noob take expensive digital scope.
I have analyzed signal, made diagnose and repaired this machine before this noob have find adjustments what he need for display signals for anaylze it. Then, there is things what I can not do with this Tek2465 or HP1741 (due to too slow speed for draw CRT memory and other known limits common with analog scope...)  but I can do even with Rigol DS1000E or Siglent SDS1000CML or with Owon SDS7102 or even with HP54200

No one can know what is best for some buyer until  needs are specified.

This way here - it can not do.

I can think or quess what is perhaps good to OP but I do not say it because I do not know enough about OP's needs etc.

VW is  one of most popular car here. But it is not for me even when lot of peoples like it. I do not select just because "all like".
Also I do not have swiss knife even if it is handy but it is not very good in anything.

[2N3055]

rf-loop

I don't think anybody could have said it better!!

I agree 100 %..

[nctnico]

Once I designed and built from scratch a fully functional personal computer using only an analog multimeter and logic probe so am very skeptical of  'you must have X' statements.

These kind of statements always make me wonder about how much time would have been saved by having the right equipment. Also being able to make the right measurements helps to verify a design. All in all having good tools makes building something easier and quicker. I don't understand why someone should buy a limited piece of equipment because a couple of grey beards didn't had much equipment either because back then it wasn't affordable. Making-do comes at a price: time. So in the end it comes down to how much is your time worth?

[rstofer]

In my view, scopes under 100 MHz are pretty useless...

That's an extreme statement. Basically you imply that having a 70Mhz DSO is about the same as not having a DSO at all.  My 60Mhz TDS210 served me very well and I would keep using if I could.

Too much focus on equipment and feature list IMO rather what we design build and learn.

Well, I did say 'In my view...'.  MY projects are all digital or very low frequency analog, VERY LOW frequency.  Watch it on a V-O-M meter slow.  All of my digital projects run over 50 MHz even though the external signals seldom get over 20 MHz.  So, yes, anything less than 100 MHz is pretty useless if I want to be able to display something that looks somewhat like a square wave.  In some cases, I really do care about setup and hold time relative to the clock and that's a lot easier to do when square edges look square.  I have no interest in RF and even less in audio.  Again, "In my view...".  Other opinions willl vary.

Features are the entire reason for buying a DSO.  DSOs will never be the same as analog scopes so there had better be some reason for all the interest.  In fact, it's the features!  Single shot, infinite persistence is one.  Measurements is another. It's all about the features...

There are plenty of fine analog scopes on the used market.  I bought my 485 via eBay about 12 years ago.  It still works well.  But it has no features and, again, for my purposes, it isn't overly helpful with only two channels.  It's fast but it doesn't have features.

In the end it gets down to price.  Sure, I'd love to have a 500 MHz Keysight MSO but that's not realistic for my level of interest in this hobby.  What is realistic is a low end scope with decent bandwidth and features.  Plus 4 channels.  If I wasn't gaining channels and features, why bother?

Of course I can get by with less.  I've been doing it the hard way for decades.  But the capabilities of the modern DSO, even an entry level version like the DS1054Z, make buying a DSO very attractive.  Attractive at $400, maybe not for $1200...   It's just a hobby, one of several.

Sure, the 60 MHz TDS 210 is a good scope.  Nothing wrong with it!  But, realistically, if I couldn't buy one for $100, I wouldn't bother.  Even then, I would want to compare the feature list against the DS1054Z and see how they stack up.  Prices on eBay are all over the map but tend toward a number where I would just go for a more modern scope.  The 210 doesn't do anywhere near as many measurements as the 1054Z.  Nowhere close!  So, maybe $200 for a used 210 or $400 for a new 1054Z - that's the fundamental question.  OTOH, if I had the TDS210, I might not be looking for an upgrade just yet.  It does have some features.  Record length isn't one of them...

At this point, I'm pretty down on recommending used scopes.  Some of our members have had less than stellar results.  I'm happy with my $200 Tek 485 but I think I just got lucky!  Others have had different results.

It's pretty easy to recommend 100 MHz as a lower end because it comes in such an inexpensive package along with a ton of features and 4 channels.  Of course I'm going to recommend the DS1054Z or something similar.  And, at this point, I'm not going to be recommending used scopes at all.

[zapta]

...Making-do comes at a price: time. So in the end it comes down to how much is your time worth?

My hobby time is very cheap. It's about satisfaction, not productivity.  That's why mentioned that my use case is hobby.

I don't understand why someone should buy a limited piece of equipment because a couple of grey beards didn't had much equipment either because back then it wasn't affordable.

1. I don't have beard, gray or any other color.
2. I am using an oscilloscope, it's a nice R&S 100Mhz two channel that I preferred over a 4 channel Rigol.
3. All equipment is limited.
4. My point was that I am skeptical of blanket 'you must have feature X' statements. People's needs, goals, priorities, and preferences are much more diverse than that.
5. I appreciate more what people design, build and learn rather than what equipment they have. Having fancy equipment or a collection expensive 7 digits bench DMMs will not get you any points here. Building something cool and innovative will.

YMMV.

[rstofer]

More often than not. when new users ask for recommendations, they don't include any details about their applications and it's true, the applications matter.  The problem is, they probably don't know their application for today and they certainly don't know their applications for several years down the line.  We tend to recommend what we have because, hopefully, our equipment meets our needs.

The next idea is to 'future proog' the decision.  Good luck with that!  Many years ago I was warned to 'never bet against technology'.  Boy, was that right!

There's really no way around the issue of application.  The user doesn't know and neither do we.

[tggzzz]

Once I designed and built from scratch a fully functional personal computer using only an analog multimeter and logic probe so am very skeptical of  'you must have X' statements.

These kind of statements always make me wonder about how much time would have been saved by having the right equipment. Also being able to make the right measurements helps to verify a design. All in all having good tools makes building something easier and quicker. I don't understand why someone should buy a limited piece of equipment because a couple of grey beards didn't had much equipment either because back then it wasn't affordable. Making-do comes at a price: time. So in the end it comes down to how much is your time worth?

Logic probe? Luxury; they were a high-end HP product. I had to make do with LEDs when I designed and built my 6800 system with 128 bytes of RAM.

But more seriously, you are missing the indirect benefits that arise from doing more with less:

• more complex, capable tools have a steeper learning curve; that's a serious issue for a beginner
• it is better to put your money into your project than into tools for your project; the project is the objective
• having to think and deeply what is going on is a good discipline, and is very rewarding
• if you are going to be a professional engineer (cf hobbyist or technician), there will come a point where you can't just buy a tool and use it, because physics will get in the way. It is better to start thinking deeply at the outset
• sooner or later someone has to make the next generation tool using only this generation of tools (how do you make a 5 digit multimeter if the best multimeters are only 4 digits?)
• being able to explain what you did, how, and why is very very advantageous in job interviews
• an engineer is someone who can do for $1 what any fool can do for $2

[rstofer]

Once I designed and built from scratch a fully functional personal computer using only an analog multimeter and logic probe so am very skeptical of  'you must have X' statements.

These kind of statements always make me wonder about how much time would have been saved by having the right equipment. Also being able to make the right measurements helps to verify a design. All in all having good tools makes building something easier and quicker. I don't understand why someone should buy a limited piece of equipment because a couple of grey beards didn't had much equipment either because back then it wasn't affordable. Making-do comes at a price: time. So in the end it comes down to how much is your time worth?

Logic probe? Luxury; they were a high-end HP product. I had to make do with LEDs when I designed and built my 6800 system with 128 bytes of RAM.

But more seriously, you are missing the indirect benefits that arise from doing more with less:

• more complex, capable tools have a steeper learning curve; that's a serious issue for a beginner

True enough but those features don't have to be used.  I clearly don't have any idea how to use all, or even many, of the features of a modern DSO.  It's a work in progress1  In the meantime, I benefit from the features I do understand.

• it is better to put your money into your project than into tools for your project; the project is the objective

This is seldom true for me.  I am only interested in projects up to the 90% level.  I want to learn about the techniques and have very little interest in the completed project.  True, that's just me but I suspect there are others out there.

• having to think and deeply what is going on is a good discipline, and is very rewarding

Taking away an important sense like sight is a definite handicap.  Sure, you can do electronics without a scope but as the projects get more complex, the handicap is more profound.

• if you are going to be a professional engineer (cf hobbyist or technician), there will come a point where you can't just buy a tool and use it, because physics will get in the way. It is better to start thinking deeply at the outset

Thinking IS important but so is seeing.  If you can't see it, it doesn't exist.  How in the world can you discover glitches without a scope.  A logic probe these days is only useful for static systems.  The LED will tell you that something changed but it won't tell you when.

• sooner or later someone has to make the next generation tool using only this generation of tools (how do you make a 5 digit multimeter if the best multimeters are only 4 digits?)
• being able to explain what you did, how, and why is very very advantageous in job interviews
• an engineer is someone who can do for $1 what any fool can do for $2

And spends $100 on the tools to do it and $1000 on the labor.  My hobby time does have value.  As I get older, my labor rate goes up.[/list]

[tggzzz]

Once I designed and built from scratch a fully functional personal computer using only an analog multimeter and logic probe so am very skeptical of  'you must have X' statements.

These kind of statements always make me wonder about how much time would have been saved by having the right equipment. Also being able to make the right measurements helps to verify a design. All in all having good tools makes building something easier and quicker. I don't understand why someone should buy a limited piece of equipment because a couple of grey beards didn't had much equipment either because back then it wasn't affordable. Making-do comes at a price: time. So in the end it comes down to how much is your time worth?

Logic probe? Luxury; they were a high-end HP product. I had to make do with LEDs when I designed and built my 6800 system with 128 bytes of RAM.

But more seriously, you are missing the indirect benefits that arise from doing more with less:

• more complex, capable tools have a steeper learning curve; that's a serious issue for a beginner

True enough but those features don't have to be used.  I clearly don't have any idea how to use all, or even many, of the features of a modern DSO.  It's a work in progress1  In the meantime, I benefit from the features I do understand.

I occasionally show beginners how to use scopes. I observe that they don't know what it is "safe" to ignore at this stage vs what they actually need to know. Too many options completely confuses them, to the point they can't "see the wood for the trees" and do simple tasks.

• it is better to put your money into your project than into tools for your project; the project is the objective

This is seldom true for me.  I am only interested in projects up to the 90% level.  I want to learn about the techniques and have very little interest in the completed project.  True, that's just me but I suspect there are others out there.

• having to think and deeply what is going on is a good discipline, and is very rewarding

Taking away an important sense like sight is a definite handicap.  Sure, you can do electronics without a scope but as the projects get more complex, the handicap is more profound.

• if you are going to be a professional engineer (cf hobbyist or technician), there will come a point where you can't just buy a tool and use it, because physics will get in the way. It is better to start thinking deeply at the outset

Thinking IS important but so is seeing.  If you can't see it, it doesn't exist. 

There are many many things that exist that I can't observe directly. Start by considering electromagnetic fields in enclosures and filters, and all the tricks of the trade associated with microwave design (and that includes digital systems, of course).

How in the world can you discover glitches without a scope. 

You think about what the root causes of glitches are and how to avoid them.
You implement the design in small steps, one gate at a time, and test each step before moving the next step.
That's standard engineering practice; softies have triumphantly reinvented that wheel and think TDD is novel. Sigh.

Anybody that throws the whole design together and tries to debug the totality is likely to be disappointed.

A logic probe these days is only useful for static systems.  The LED will tell you that something changed but it won't tell you when.

I have a logic probe; I don't recall using it. To me they are only a conveniently packaged LED. HP did have "signature analysers", but they were a production testing, not design.

• sooner or later someone has to make the next generation tool using only this generation of tools (how do you make a 5 digit multimeter if the best multimeters are only 4 digits?)
• being able to explain what you did, how, and why is very very advantageous in job interviews
• an engineer is someone who can do for $1 what any fool can do for $2

And spends $100 on the tools to do it and $1000 on the labor.  My hobby time does have value.  As I get older, my labor rate goes up.

That is, of course, an interesting valid personal consideration - and I have some sympathy with it! But for many people the advantages I've mentioned are important in the long term.[/list]

[tautech]

Good discussion guys. 

Yep, when we select a scope there is no doubt we will grow beyond it's capabilities.....from LV digital circuitry to HV power electronics maybe.
From analog circuitry to digital and decoding maybe.

Here, NZ we are better to have a scope that can safely withstand rectified mains (325V) and for the common protocols 2 channels plus a Trig input at least for the protocol clock.
Not high end requirements.....just the basic ones.

[nctnico]

Once I designed and built from scratch a fully functional personal computer using only an analog multimeter and logic probe so am very skeptical of  'you must have X' statements.

These kind of statements always make me wonder about how much time would have been saved by having the right equipment. Also being able to make the right measurements helps to verify a design. All in all having good tools makes building something easier and quicker. I don't understand why someone should buy a limited piece of equipment because a couple of grey beards didn't had much equipment either because back then it wasn't affordable. Making-do comes at a price: time. So in the end it comes down to how much is your time worth?

But more seriously, you are missing the indirect benefits that arise from doing more with less:

• more complex, capable tools have a steeper learning curve; that's a serious issue for a beginner
• it is better to put your money into your project than into tools for your project; the project is the objective
• having to think and deeply what is going on is a good discipline, and is very rewarding
• if you are going to be a professional engineer (cf hobbyist or technician), there will come a point where you can't just buy a tool and use it, because physics will get in the way. It is better to start thinking deeply at the outset
• sooner or later someone has to make the next generation tool using only this generation of tools (how do you make a 5 digit multimeter if the best multimeters are only 4 digits?)
• being able to explain what you did, how, and why is very very advantageous in job interviews
• an engineer is someone who can do for $1 what any fool can do for $2

Doing more with less is like trying to tie your shoe lace with one hand. A nice trick but it won't land you a job. There are more than enough engineering challenges left in a typical project that require ingenuity. Better concentrate on those than wasting time on trivial things due to lack of good tools (if you have the money to spend on tools ofcourse).

[rstofer]

By the time a new user decides to buy a scope, I would have to assume they have come up against something where having a scope would be a benefit.  After all, they're about to part with serious money!

There is no question that the modern DSO has a ton of features!  It will be months, if not years, before I find my way around the DS1054Z and that's just an entry level scope.  OTOH, I can do the things I need to do and only rarely stumble on finding the proper menu.

All the newcomer needs to know is to connect the signal and press Auto - everything else will work out fine.  Once the trace is on the screen, they can diddle with time/div or volts/div.  No, I'm not entirely serious but it is true.  I use Auto all the time.  Primarily because I will have left the scope in some obscure more with a lot of settings having been messed with.

So, wander around Google, or even this forum, and find tutorials and videos.  That's how everybody learns anything these days.  Google has more than 13 million hits on "how to use a DSO".  Toss out half as nonsense and there are still a few millions hits.

I certainly wouldn't recommend backing up to a dual channel CRO just to get rid of features.

As it turns out, the Rigol DS1000Z manual is pretty well written.  RTFM comes to mind!

[tggzzz]

Once I designed and built from scratch a fully functional personal computer using only an analog multimeter and logic probe so am very skeptical of  'you must have X' statements.

These kind of statements always make me wonder about how much time would have been saved by having the right equipment. Also being able to make the right measurements helps to verify a design. All in all having good tools makes building something easier and quicker. I don't understand why someone should buy a limited piece of equipment because a couple of grey beards didn't had much equipment either because back then it wasn't affordable. Making-do comes at a price: time. So in the end it comes down to how much is your time worth?

But more seriously, you are missing the indirect benefits that arise from doing more with less:

• more complex, capable tools have a steeper learning curve; that's a serious issue for a beginner
• it is better to put your money into your project than into tools for your project; the project is the objective
• having to think and deeply what is going on is a good discipline, and is very rewarding
• if you are going to be a professional engineer (cf hobbyist or technician), there will come a point where you can't just buy a tool and use it, because physics will get in the way. It is better to start thinking deeply at the outset
• sooner or later someone has to make the next generation tool using only this generation of tools (how do you make a 5 digit multimeter if the best multimeters are only 4 digits?)
• being able to explain what you did, how, and why is very very advantageous in job interviews
• an engineer is someone who can do for $1 what any fool can do for $2

Doing more with less is like trying to tie your shoe lace with one hand. A nice trick but it won't land you a job.

There you're wrong. Of the 7 jobs I've had the indirect benefits were directly instrumental in landing me the the three most interesting: my first, at Cambridge Consultants, and at Hewlett-Packard Laboratories.

And at the latter the disadvantages of having "too much" equipment was noted by many denizens. A slightly unusual situation, I'll agree, but so was my doing all the paperwork to import munitions

There are more than enough engineering challenges left in a typical project that require ingenuity. Better concentrate on those than wasting time on trivial things due to lack of good tools (if you have the money to spend on tools ofcourse).

Choosing the "right" tools is a key engineering skill.

All too often "right" means "what is available instantly" - and then you often have to find inventive way to solve the task with whatever tools happen to be at hand.

[rstofer]

Doing more with less is like trying to tie your shoe lace with one hand. A nice trick but it won't land you a job. There are more than enough engineering challenges left in a typical project that require ingenuity. Better concentrate on those than wasting time on trivial things due to lack of good tools (if you have the money to spend on tools ofcourse).

Tools at any level are cheaper than wages.  I'm long retired but if I were an engineering manager, I would be buying better tools.  Two reasons: Tools reduce the cost of engineering and, more important, tools are capital equipment and don't come out of Wages & Salary.  All my department has to pay is the depreciation.  I can buy a $100,000 scope for the 10 year depreciation or about $10,000 out of my budget.  I can't get more than a month of wages for that kind of money and all I need to do is save one month's (and benefits) each year for 10 years!

Can the scope save a month's wages per year?  Probably...

But the equation for the hobbyist is vastly different...

[tggzzz]

By the time a new user decides to buy a scope, I would have to assume they have come up against something where having a scope would be a benefit.  After all, they're about to part with serious money!

Often people have a burst of enthusiasm and are prepared to spend significant money on a wetsuit/windsurfer, a camera, gym membership, RC aircraft, etc. All too often these shiny new toys are left to gather dust in the cupboard. "Too complicated" increases the chances that dust will be gathered.

There is no question that the modern DSO has a ton of features!  It will be months, if not years, before I find my way around the DS1054Z and that's just an entry level scope.  OTOH, I can do the things I need to do and only rarely stumble on finding the proper menu.

With a well-designed tool, I would hope that would be the case. But the pre-requisite is that you know what you don't need to know and so know what you can safely ignore.

Beginners don't have that knowledge.

All the newcomer needs to know is to connect the signal and press Auto - everything else will work out fine.  Once the trace is on the screen, they can diddle with time/div or volts/div.  No, I'm not entirely serious but it is true.  I use Auto all the time.  Primarily because I will have left the scope in some obscure more with a lot of settings having been messed with.

The latter "rescue me using reset" is valid.

The "auto" will show something, but whether it is what the user needs to see is a separate issue.

[tggzzz]

Doing more with less is like trying to tie your shoe lace with one hand. A nice trick but it won't land you a job. There are more than enough engineering challenges left in a typical project that require ingenuity. Better concentrate on those than wasting time on trivial things due to lack of good tools (if you have the money to spend on tools ofcourse).

Tools at any level are cheaper than wages.  I'm long retired but if I were an engineering manager, I would be buying better tools.  Two reasons: Tools reduce the cost of engineering and, more important, tools are capital equipment and don't come out of Wages & Salary.  All my department has to pay is the depreciation.  I can buy a $100,000 scope for the 10 year depreciation or about $10,000 out of my budget.  I can't get more than a month of wages for that kind of money and all I need to do is save one month's (and benefits) each year for 10 years!

That's a very important calculation, particularly if spending more money means hitting the market sooner and capturing more of the market.

But with any new tool you have to factor in the learning curve and how that affect the time-to-market etc. In a professional setting often there is probably existing experience on similar tools, so the learning curve can be minimal. But for some tools, especially CAD, learning which sequence of buttons to press varies radically from one tool to the next. In such cases it can be better to stick with imperfect existing tools.

Can the scope save a month's wages per year?  Probably...

Yes, repeat no. Depends on the tool and the circumstances. A scope, probably yes

[rstofer]

Can the scope save a month's wages per year?  Probably...

Yes, repeat no. Depends on the tool and the circumstances. A scope, probably yes

Where I worked, we never did post-mortems on business decisions or project payback.  We moved on...  In other words, if I, as the engineering manager, said that the scope had saved money, that was the end of the discussion.  On to more important topics.  True, I didn't work in electronics but the management style was just as I said.  Win, lose, draw but by all means, move on!

[nctnico]

As a side note: the most succesful employers I worked for spend money on getting good equipment. I do the same: if I foresee a project needs special equipment I make sure I have it.

[zapta]

As a side note: the most succesful employers I worked for spend money on getting good equipment. I do the same: if I foresee a project needs special equipment I make sure I have it.

1. 'need' is not always a binary function. Often there are many options, variables and possibilities.

2. Naturally successful companies have money for fancy equipment.

3. Don't mix hobby and professional scenarios.

4. Nobody here opposes to or suggests to ban 4ch scopes.

The world is not black and white, many shades of gray and possibilities in between.

[David Hess]

Well, I did say 'In my view...'.  MY projects are all digital or very low frequency analog, VERY LOW frequency.  Watch it on a V-O-M meter slow.  All of my digital projects run over 50 MHz even though the external signals seldom get over 20 MHz.  So, yes, anything less than 100 MHz is pretty useless if I want to be able to display something that looks somewhat like a square wave.  In some cases, I really do care about setup and hold time relative to the clock and that's a lot easier to do when square edges look square.  I have no interest in RF and even less in audio.  Again, "In my view...".  Other opinions willl vary.

...

There are plenty of fine analog scopes on the used market.  I bought my 485 via eBay about 12 years ago.  It still works well.  But it has no features and, again, for my purposes, it isn't overly helpful with only two channels.  It's fast but it doesn't have features.

High bandwidth *is* a feature as you point out.

My analog sampling oscilloscope is in no way a replacement for a modern budget DSO or any of my analog and digital storage oscilloscopes but when high bandwidth, clean response, or perfect overload recovery are needed, then nothing can match it.

At this point, I'm pretty down on recommending used scopes.  Some of our members have had less than stellar results.  I'm happy with my $200 Tek 485 but I think I just got lucky!  Others have had different results.

It's pretty easy to recommend 100 MHz as a lower end because it comes in such an inexpensive package along with a ton of features and 4 channels.  Of course I'm going to recommend the DS1054Z or something similar.  And, at this point, I'm not going to be recommending used scopes at all.

The only reasons I would not recommend a used analog oscilloscope are maintenance which a new user is unlikely to be prepared for and reliability unless the user is in a position to refurbish it.  In most cases a good budget Chinese DSO will be better.

[Wuerstchenhund]

And the importance of sampling rate?

It is only of marginal importance

No, it isn't. It's *one* parameter that determines the max useable real-time BW of your scope.

and is principally used as a sales headline; the front end's analogue bandwidth is the key measure.

Nope, it's not. The Front End's BW is *one* parameter

To ram home the point, many high-end scopes sample at a rate much lower than the highest frequency they can measure.

Yes, 20 years ago    Today, scopes have BWs of up to 100GHz with sample rates of up to 240GSa/s. Sampling scopes have long died out except for some very specific niches (i.e. optical high speed communication signals), and even there they have been/are subsequently replaced by real-time DSOs.

Too many years ago, I used a 25MS/s HP boat anchor to measure sub-nanosecond risetimes.

Good for you, but that is pretty much irrelevant today, unless you want to suggest people here invest in obsolete niche technology as a general purpose scope.

[Nozzer]

But, do they always have to be measured at the same time?

If you want to relate them in time, yes. Having 4 channels makes life a lot easier in many situations. The number of scopes out there with 4 channels is enormous so the choice really is a no-brainer.

To be fair with a modern MSO like the R&S 12** series, which only have 2 analogue channels,you can probe up to 8 digital channels with the Pod and use both analogue channels and the auxiliary output channel as an additional digital imput channel, so whilst you only have 2 analogue channels, you have 11 digital channels available - of course you need the software and digital probe for this. The scope's bandwidth is also software upgradable to a maximum of 300 MHz and offers 1Gs/s max on both (interleaved) analogue channels and all digital channels.

[Fungus]

To be fair with a modern MSO like the R&S 12** series, which only have 2 analogue channels,you can probe up to 8 digital channels with the Pod and use both analogue channels and the auxiliary output channel as an additional digital imput channel, so whilst you only have 2 analogue channels, you have 11 digital channels available - of course you need the software and digital probe for this. The scope's bandwidth is also software upgradable to a maximum of 300 MHz and offers 1Gs/s max on both (interleaved) analogue channels and all digital channels.

A fully pimped out R&S is a nice device. Not cheap for a hobbyist though.

[tggzzz]

And the importance of sampling rate?

It is only of marginal importance

No, it isn't. It's *one* parameter that determines the max useable real-time BW of your scope.

and is principally used as a sales headline; the front end's analogue bandwidth is the key measure.

Nope, it's not. The Front End's BW is *one* parameter

Of course; but in practice for a beginner my statement is useful. It allows them to concentrate on whether 1Gs/s or 50MHz specification will determine what they can see.

To ram home the point, many high-end scopes sample at a rate much lower than the highest frequency they can measure.

Yes, 20 years ago    Today, scopes have BWs of up to 100GHz with sample rates of up to 240GSa/s. Sampling scopes have long died out except for some very specific niches (i.e. optical high speed communication signals), and even there they have been/are subsequently replaced by real-time DSOs.

What are you talking about? They are all sampling scopes. Old ones used diode bridges to sample, new ones like the HP boat anchor use ADCs.

And yes, I was referring to things like high speed comms signals.

Too many years ago, I used a 25MS/s HP boat anchor to measure sub-nanosecond risetimes.

Good for you, but that is pretty much irrelevant today, unless you want to suggest people here invest in obsolete niche technology as a general purpose scope.

Thats a strawman argument, based on a reflex reaction to speed reading what I wrote and falsely interpolating things I didn't write.

[David Hess]

Yes, 20 years ago    Today, scopes have BWs of up to 100GHz with sample rates of up to 240GSa/s. Sampling scopes have long died out except for some very specific niches (i.e. optical high speed communication signals), and even there they have been/are subsequently replaced by real-time DSOs.

What are you talking about? They are all sampling scopes. Old ones used diode bridges to sample, new ones like the HP boat anchor use ADCs.

And yes, I was referring to things like high speed comms signals.

It is unfortunate that DSO could mean either digital sampling oscilloscope or digital storage oscilloscope.  In the past, "sampling" oscilloscopes referred to a very specific design where sampling occurred before attenuation and amplification so bandwidth was limited only by the sampling strobe width or transition time producing a non-linear but very predictable sin(x)/x frequency response.  They also have clean transient response and immunity to non-destructive overload.

As Wuerstchenhund points out, these oscilloscopes have been replaced by real time designs except in applications where their higher bandwidth for a given price makes up for their limitations.  The cheapest 12 GHz oscilloscope Tektronix sells is about $100k while you can buy a 12 GHz "sampling" oscilloscope from Picotech for $10k.  If used instruments are considered, then a 12 GHz sampling oscilloscope can be had for less than $1000; I bought mine for $400.

I keep hoping one of the budget DSO makers will add a sampling input to one of their instruments but I guess there is no market for 4 GHz of bandwidth at a budget price.

Update: Quotes fixed, I think.