I had a continuous/synchronous sweep scope too (one with a "sync" knob that controlled analog coupling of the input signal with the horizontal oscillator). Used them way back when. I have used all sorts of analog scopes including analog storage. Use digital scopes too. See no reason for creating arbitrary personal word definitions when many people understand differences between different types of scope tech yet accept common use of the word oscilloscope.
With that, I will leave off here.
With that, I will leave off here.
Last edited:
Well, we disagree.
Because a "digital oscilloscope" was named by marketing people, we have to deal with what we have in front of us. You and I know the difference, as do many other experienced people. But others just learning do not and the "DSO" term is confusing an misleading. If you don't treat is as a digital acquisition system, it will bite you. To avoid confusion, the differences must be highlighted. This is all I m doing.
They do not operate the same, with various settings they can and will lie to you. The less expensive models will be worse for this.
My old Philips PM-3070 was a lot more expensive than many digital oscilloscopes being talked about. It was also a much better oscilloscope for analogue signals. Same for other good analogue oscilloscopes. So to expect higher performance from a cheaper product that has many built-in issues is not reasonable. Toys (features)? Those are cheap. Performance costs money.
The basic problem is assuming an "oscilloscope" is the same instrument as a "digital oscilloscope". They aren't even close, the confusion is in similar knob labeling and display format. If you don't understand how an instrument works, it will very probably be lying to you at least some of the time.
Because a "digital oscilloscope" was named by marketing people, we have to deal with what we have in front of us. You and I know the difference, as do many other experienced people. But others just learning do not and the "DSO" term is confusing an misleading. If you don't treat is as a digital acquisition system, it will bite you. To avoid confusion, the differences must be highlighted. This is all I m doing.
They do not operate the same, with various settings they can and will lie to you. The less expensive models will be worse for this.
My old Philips PM-3070 was a lot more expensive than many digital oscilloscopes being talked about. It was also a much better oscilloscope for analogue signals. Same for other good analogue oscilloscopes. So to expect higher performance from a cheaper product that has many built-in issues is not reasonable. Toys (features)? Those are cheap. Performance costs money.
The basic problem is assuming an "oscilloscope" is the same instrument as a "digital oscilloscope". They aren't even close, the confusion is in similar knob labeling and display format. If you don't understand how an instrument works, it will very probably be lying to you at least some of the time.
Which worked differently than the modern digital storage.
Which personal word definitions are you referring to?
I think it's reasonable to divide oscilloscopes into analog and digital types because they work in fundamentally different ways. There is a difference between showing a continuous waveform in glowing phosphor that starts at some point in time determined by the trigger and sampling a waveform every fraction of a second and processing it to display it on a screen. Many of the early digital scopes had issues with aliasing. I haven't run into that in my current scope, but it's not like the problem went away. The scope software just became better at showing you something useful rather than whatever garbage came through the ADC at the time.
Tom
well tell me if i missed something in my operation of an analogue oscilloscope....
i was trying to measure slew rate using a 10KHz square, as i change the time base, i have to keep moving the trace so i can see the rising edge.
by the time i get to 5uS, i cant move the trace any more - ideally i want it at 1uS per div.
did i miss a trick???
Yes I did. Because they are both oscilloscopes. I'm curious how that's a personal word definition.
Magnetic tape, vinyl records, minidisc, and CDs are all examples of source materials. The players for each would be sources in a hifi system. Yet, players for magnetic tape and vinyl records would be considered analog sources and minidisc and CD players would be considered digital sources. There are advantages and drawbacks of each. Same with oscilloscopes. How's this a personal word definition?
Tom
Magnetic tape, vinyl records, minidisc, and CDs are all examples of source materials. The players for each would be sources in a hifi system. Yet, players for magnetic tape and vinyl records would be considered analog sources and minidisc and CD players would be considered digital sources. There are advantages and drawbacks of each. Same with oscilloscopes. How's this a personal word definition?
Tom
If your scope can't go faster than 5 µs/div, you need a faster scope. Usually that means one with higher bandwidth, though, what you're actually after is a faster time base.
Tom
Seems like I recently read where someone opined to the effect a DSO is not an oscilloscope (rather its a data acquisition system with a display)?
Personally, I'm okay with classifying both analog and digital oscilloscopes as within the genus oscilloscope.
Just a difference of opinion on how to best introduce the differences to newbies, I guess.
Last edited:
Here's a scope that challenges definition. Is it analogue or digital?
http://www.chawei.com.tw/pdf/iwatsu/pdf/ts-81000.80600.pdf
Ebay Link
Seller is open to offers! You know you want it!
I have long hankered after one. Aside from the cost, it's a bit of a beast that will take up a lot of your bench, just so you can tell your friends that you have the world's weirdest scope.
http://www.chawei.com.tw/pdf/iwatsu/pdf/ts-81000.80600.pdf
Ebay Link
Seller is open to offers! You know you want it!
I have long hankered after one. Aside from the cost, it's a bit of a beast that will take up a lot of your bench, just so you can tell your friends that you have the world's weirdest scope.
Yes, analog are mostly plain oscilloscopes, digital ones are all storage 'scopes, a.k.a. DSO, 'digital storage oscilloscope', with many sub-types such as mixed-signal, etc. Being a storage 'scope means single brief transients can be captured easily, not just repeating waveforms.
There are also sampling 'scopes of both analog and digital flavours which can resolve much finer timescales but only for strictly repetitive waveforms.
There are also sampling 'scopes of both analog and digital flavours which can resolve much finer timescales but only for strictly repetitive waveforms.
I don't know what you've read. Perhaps you could post a link.
Marketing blurb says: "State of the art Analog Storage Oscilloscope with Ultra-high brightness!". I'd agree with that. The scope is fundamentally an analog scope. It has a digital capture device to capture, display, and store images. That's pretty clear from the block diagram on the first page.
The TEK 2465 is another example of a digital/analog hybrid or digitally assisted analog scope. I think it's just the cursors and readouts that are digital, though. The scope part is still analog as far as I remember (which could be wrong). It's not high enough priority for me that I want to go and dig out the service manual to find out.
Nobody said it was a perfect analog versus digital dichotomy. All I was curious about was how analog and digital scopes were somehow a matter of personal word definition.
Tom
yes, it can do 1uS (and less) - but the rising edge is gone, only flat top/bottom of the squarewave is displayed.
Hi ctrlx,
Depends on your scope and delay setting I guess. You're trying to look at just the bleeding rising slope, pretty extreme. Since I haven't done that and I don't have your model of 'scope ... pretty fast rise time.
Depends on your scope and delay setting I guess. You're trying to look at just the bleeding rising slope, pretty extreme. Since I haven't done that and I don't have your model of 'scope ... pretty fast rise time.
It is very simple to decide.
An analogue scope displays the signal without sampling, in real time, perhaps with a delay. A digital oscilloscope samples the waveform and stores the digital result as a record of values vs time intervals. It can then display the information any way you want. Sampling oscilloscopes are differentiated by their name, another beasty.
It is the act of sampling the signal and storing the value during that time slot as a number (limited by the resolution of the ADC). You don't need to complicate it any more than that.
An analogue scope displays the signal without sampling, in real time, perhaps with a delay. A digital oscilloscope samples the waveform and stores the digital result as a record of values vs time intervals. It can then display the information any way you want. Sampling oscilloscopes are differentiated by their name, another beasty.
It is the act of sampling the signal and storing the value during that time slot as a number (limited by the resolution of the ADC). You don't need to complicate it any more than that.
The old analog storage scopes could work like a standard analog scope, or else in storage mode.
I'll throw out a thought. Are you triggering on falling (the leftmost side of the screen) and wanting to see rising edge. Rising will be delayed 50uS from falling if symmetrical. 10 divisions is normal for a scope x 5uS/div is 50uSec. I mentioned this before but no one seemed to notice. In an analog scope, trigger happens at left edge. There is usually a very small (think pS) delay in the channel relative to the trigger, so for very high speed edges you can catch them. DSO's on the other hand sample continuously, and so when trigger happens it is usually in the center of the screen with before and after trigger displayed. DSO's can move that location usually. This is again a case where the DSO is easier to use in my opinion. Hope this doesn't "trigger" anyone.😀
must be a 7A22N or 5A22N plug-in. One of the most useful pieces of Tektronix equipment.
Tek made a killing on the 4014 terminals with their storage technology. You can to this day emulate it on a Xterm. I recall using one in school in the 70's. Big thing. Not great either, monochrome(well green) and got burn spots pretty easily.
Hi mikeAtx,
Many better analogue oscilloscopes have a delay line so it acts similarly to the pretrigger information a DSO has. You can display the signal before the triggering event on those.
I start the "sweep" on the left on my DSO's. They still show a bit more to the left of the trigger when you do that.
Many better analogue oscilloscopes have a delay line so it acts similarly to the pretrigger information a DSO has. You can display the signal before the triggering event on those.
I start the "sweep" on the left on my DSO's. They still show a bit more to the left of the trigger when you do that.
How long is the delay though? As I said, common to get some pS, not uS. I worked on some scopes back in school that had them. They ran the depth of the scope, which was not a shoebox!
Not surprised you set the DSO trigger to the left. It would feel more normal I suspect for you since you run analog most of the time. I still if I have a very slow sweep (.1S/div) can be a little confused as display is held until trigger time and then the entire left screen appears. As I've said and you've said, you have to know what the tool is doing. RTFM.
Not surprised you set the DSO trigger to the left. It would feel more normal I suspect for you since you run analog most of the time. I still if I have a very slow sweep (.1S/div) can be a little confused as display is held until trigger time and then the entire left screen appears. As I've said and you've said, you have to know what the tool is doing. RTFM.