Author Topic: Do You still use analog oscilloscopes in 2019?  (Read 9209 times)

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Offline Mr. Scram

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #50 on: July 30, 2019, 10:39:00 pm »
Sigh. Do you really think context is the last post and the last post alone? It seems you would feel at home on stack exchange.

To reiterate the point, including only the last post removes the context in which the last post was made.

So, you do contend that my screenshot indicates that there is a "blurring of the lines" between clocks, discs, processors, memory, networks and thermometers! Bizarre.
I've neither confirmed nor denied that assertion. Do you contend the new Keithley DMM, DAQ and SMU ranges are actually oscilloscopes? Who controls these definitions for each device type and where can they be found? It seems you'd end up like biologists, desperately trying to come up with definitions that'll lead to discrete species but being thwarted by nature every time
« Last Edit: July 30, 2019, 10:40:52 pm by Mr. Scram »
 

Online tggzzz

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #51 on: July 30, 2019, 11:12:15 pm »
Sigh. Do you really think context is the last post and the last post alone? It seems you would feel at home on stack exchange.

To reiterate the point, including only the last post removes the context in which the last post was made.

So, you do contend that my screenshot indicates that there is a "blurring of the lines" between clocks, discs, processors, memory, networks and thermometers! Bizarre.
I've neither confirmed nor denied that assertion.

Ignoring counter examples never looks good.

Quote
Do you contend the new Keithley DMM, DAQ and SMU ranges are actually oscilloscopes? Who controls these definitions for each device type and where can they be found? It seems you'd end up like biologists, desperately trying to come up with definitions that'll lead to discrete species but being thwarted by nature every time

I'm afraid I don't keep abreast of all manufacturers latest products displaying incremental changes from previous products, so I can't comment on the Keithley products. But do they market and sell them as oscilloscopes? What are their triggering facilities?

Having said that, most people would agree on the key distinctions between an oscilloscope and a logic analyser: one captures analogue waveforms, the other interprets analogue waveforms as digital signals and filter and post-process those digital signals.
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Offline Mr. Scram

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #52 on: July 30, 2019, 11:29:04 pm »
Ignoring counter examples never looks good.

I'm afraid I don't keep abreast of all manufacturers latest products displaying incremental changes from previous products, so I can't comment on the Keithley products. But do they market and sell them as oscilloscopes? What are their triggering facilities?

Having said that, most people would agree on the key distinctions between an oscilloscope and a logic analyser: one captures analogue waveforms, the other interprets analogue waveforms as digital signals and filter and post-process those digital signals.
The difference between your example and mine is that the Saleae devices are explicitly marketed as a logic analyser and clearly were incrementally developed from other logic analysers. The Keithleys are marketed as DMMs, but have the ability to display voltages continuously over time at 1MS/s. They also possess triggering capabilities like the triggering on rising or falling edges commonly found in oscilloscopes. Those elements are arguably what historically defined oscilloscopes. Advances in technology blur the lines and change already loose definitions.

 

Offline David Hess

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #53 on: July 31, 2019, 01:21:05 am »
I will bite.  I have several analog oscilloscopes and digital storage oscilloscopes but will mostly discuss my 2232 in analog mode:

1. It was only $120.  Of course at this price you have to be prepared to refurbish the instrument yourself.
2. The display and controls operate in real time.  REAL TIME!  Do you know what that means?  Latency for either never spikes.  I never have to wait for the oscilloscope to respond to my next action or second guess it.
3. It boots in 7 seconds in analog or DSO mode.
4. The display was a retina display, in analog or digital mode, before Apple invented it.
5. The analog grading means it can make RMS noise measurements in analog mode of voltage or time using the tangent method reliably and to good accuracy.  I have used this to verify that DSOs are measuring RMS noise correctly and to make spot noise measurements.
6. The response of the automatic peak-to-peak triggering mode is fantastic and not duplicated in any DSO and few analog oscilloscopes since.  Automatic peak-to-peak triggering also tracks signal levels continuously.  This means no waiting when moving a probe between signals for the display to stabilize.  Later oscilloscopes, including analog oscilloscopes from Tektronix, implement automatic level triggering which is pitifully slow in comparison.
7. The transient response is excellent.  This is a time domain instrument so this is what matters.

Nothing prevents a modern low cost DSO from doing most of the above except programming.

(1) And analog storage and analog sampling and digital sampling oscilloscopes but let us keep things simple.
 

Offline Cubdriver

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #54 on: July 31, 2019, 01:33:14 am »
I have two DSOs.  All the rest are analog, and analog is what I tend to use more often than not.  Main workhorses are a Tek 2246 and a 2465A; if I use a digital it's normally my TDS 3032.  Older tube-type Teks get played with occasionally for fun and variety (and more in the winter).  7000 series are waiting in the queue to eventually be wrung out and go into the rotation.  And I just got an HP 140A last week.

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Offline graybeard

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #55 on: July 31, 2019, 03:36:46 am »
For my home lab I use my 500 MHz 7904A whenever I want to look at signals that are too fast or not viewable for other reasons with my Siglent SDS1104X-E.   

Where I work we no longer have analog scopes available in the pool.  I currently have a 300MHz R&S RTB2004 checked out which is an excellent scope, and have access to many models from Tek and Keysight.  A few weeks ago I used a Keysight 15 GHz model.

I have a 1GHz (500 MHz in the 7904A) 7A29 50 Ohm plugin with 800ps rise time.  I also have 2 7A26 200MHz dual channel plug-ins, a 7A11 250 MHz FET probe plug-in, a late-model 7A13 105 MHz differential input plug-in, a 7D11 digital delay, a 7B92 500ps/div time base that is the best triggering time-base I have used in any analog scope, and a 7B50 time base that is very easy to adjust for low frequency signals.

Before I bought the Siglent, I only used the 7904A.  Since I bought the Siglent, it is the scope I primarily use at home.  However the old TEK has capabilities that I still need and use, especially with the special purpose plug-ins.  I also sometimes use to verify what I am seeing on my Siglent because my many years of analog scope use I have a much larger mental database of what to expect. 

If I had the RTB2004 at home I would use the 7904A even less frequently than I do, since most time I use it is for the greater bandwidth and 300MHz would be enough for 95% of things I do at home.
« Last Edit: July 31, 2019, 03:44:37 am by graybeard »
 

Offline Tom45

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #56 on: July 31, 2019, 03:52:17 am »
9 out of 10 cats prefer Tek Analog scopes.

7854 with cat plugin

799122-0

2 cats with 7844, 2232, and 7903 in background.

799128-1
 
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Offline Brumby

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #57 on: July 31, 2019, 04:27:22 am »
To answer the Op: Yes.

I have an HP1740A analogue scope (courtesy of Dave) that superceded my Hitachi V152B as my first 'go to'.  It has selectable 50ohm inputs which make a huge difference when frequencies start getting up there.  The first time I tried these out, I was amazed at the difference between the trace when using those and using a 50 ohm terminator on the opposite side of a BNC T connector.

These 2 scopes have covered the majority of my needs - which, I admit, aren't all that demanding - for many years.

In the digital range, I do have a Hantek 6022B USB scope and a DSO138 which have their place (not at the front line) plus a Tek TDS220 courtesy of another member here which I haven't learned to drive properly yet ... but, then, I haven't needed to.


I suppose the best way to answer you is to say - if you already have a scope and don't know why you need to go digital, then you quite probably don't.  At least not yet.
 

Offline 0culus

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #58 on: July 31, 2019, 04:29:10 am »
I actually don't even have a digital scope, except at work. :) My "stable" consists of a 7904A mainframe with a selection of plugins (more on the way soonish I hope), 2465B, and the rather uncommon HP 1727A storage 'scope.
 

Offline bob91343

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #59 on: July 31, 2019, 04:33:50 am »
Ah yes the 1727A.  I just sold mine because I never used it.  A rare analog storage oscilloscope, tiny screen, very fast.
 

Offline Brumby

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #60 on: July 31, 2019, 04:58:21 am »
What was really happening with the cats....

 
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Offline BU508A

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #61 on: August 02, 2019, 02:20:52 pm »
I still use one occasionally, my primary scopes are DSOs but the XY mode on my analog scope blows away every DSO I've tried for that purpose.

I made ths screenshot from my RTB 2004 in X-Y Mode. No idea, what's wrong with that.   :-//

It doesn't look that great to me (maybe if C2 was higher amplitude and less noisy). If that's the best it can do on a simple phase shifted sinewave then I wouldn't want to use if for any sort of complex X-Y function.

just for comparison: I've assembled two 1kHz sine wave gen and connected them to my scopes,
a RTB2004 100MHz and a Tektronix 2465B bot in X-Y mode.

The RTB 2004:



The 2465B:


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Online Kleinstein

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #62 on: August 02, 2019, 04:58:51 pm »
The last X-Y mode plots look like there is quite some jitter problem. I would guess this could be more like a generator problem. The old analog scope also shows so some distortion - which is more like a scope problem than from the generator - on the DSO the waveform looks reasonably OK.

When using XY mode one usually should turn to single channel. This would remove the extra diagonal on most scopes.
 

Offline rstofer

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #63 on: August 02, 2019, 05:09:33 pm »
Affordable DSOs have features, affordable analog scopes (used) have bandwidth.  I have been using a Tek 485 (350 MHz) analog scope for at least the last 12 years.  It cost about $200 on eBay.  Today I primarily use a 100 MHz (unlocked) Rigol 1054Z and it has both features and channels.  It's a great scope for low frequency work.

There is no comparison between the scopes.  One is a master of measuring, displaying and decoding.  The other is fast.

The big feature of the DSO is Single Shot.  It turns out I use that more than any other feature.
 

Offline DaJMasta

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #64 on: August 02, 2019, 05:24:19 pm »
Haven't owned one in my life, none of the reasons to own one has been compelling enough for me to do so.  Storage, measurement, and analysis options are also just too powerful for me to ignore when considering a scope purchase.


I get nostalgia, I get that they are sufficient for most tasks, and I get that some things like X-Y mode are often implemented better... none of those are enough for me, and in my experience, decent DSOs can do plenty well.  I've got a generation old Rigol and a 15 year old higher bandwidth LeCroy and while there are some features/performance I envy in other scopes, I'm covered pretty well for my use cases and none of the things I'm looking for are available in an analog scope.
 

Online maginnovision

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #65 on: August 02, 2019, 05:35:51 pm »
I have a Tek 475A with DM44 and manuals but it almost never gets used other than drawing things thanks to the excellent xy(z) mode. I keep thinking about getting rid of it but what a hassle. So essentially, no, I don't use an analog scope anymore.
 

Offline george.b

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #66 on: August 02, 2019, 07:25:09 pm »
I have one analog and one DSO. Both are ancient. I used the analog one just this week to look at a video signal.
 

Online rsjsouza

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #67 on: August 02, 2019, 08:06:37 pm »
I still have my first oscilloscope Kenwood CS4025 stored somewhere but still in pristine condition. I rarely use it anymore, especially because my Rigol DS4014 does an excellent job in terms of bandwidth, color grading and response.

Part of my experience transitioning from analog to digital is here

A few additional comments about the analog vs digital are here.
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Offline BU508A

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #68 on: August 02, 2019, 08:55:17 pm »
The last X-Y mode plots look like there is quite some jitter problem. I would guess this could be more like a generator problem. The old analog scope also shows so some distortion - which is more like a scope problem than from the generator - on the DSO the waveform looks reasonably OK.

When using XY mode one usually should turn to single channel. This would remove the extra diagonal on most scopes.

The jitter has imo two main reasons:
- EMV in my lab
- I have bodged 2 independet 1kHz sine wave generators with some parts I've laying around.
  I do not own (yet) a nice function generator.



The generators have two slightly different frequencies, 996Hz vs. 978Hz and they are running freely.
This will produce this "dancing" Lissajous plot.
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Offline bsudbrink

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #69 on: August 02, 2019, 10:18:18 pm »
My 2465A has a permanent place on my bench.  I've had it professionally serviced and cal'd.  And it does this:

 

Offline 0culus

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #70 on: August 02, 2019, 10:37:31 pm »
Another thing I like about analog CROs: control inputs are immediate, and tactile. I get to spend time with two expensive digital scopes at work...I have a Tek TDS5k series 1 GHz DPO on my desk and there's a Keysight MSO-X 6k down in the lab. While both are amazingly capable, I absolutely despise having to navigate menus to find functions.  :wtf: Plus, control inputs have an annoying amount of latency between input and effect.
 

Online vk6zgo

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #71 on: August 03, 2019, 03:44:33 am »
Back in the early 1990s, when the DSO's record length wasn't deep enough (unless one paid a fortune) I was also designing analog-TV baseband circuits.

To properly see the chroma burst and static pattern in the active video, one had to use an analog scope.
Not any scope, but one which had advanced TV triggering capabilities, i.e. trigger from a specific line. But the resulting display was very dim.

For that reason, Tektronix and other manufacturers also sold waveform monitors, which were specialized scopes for the purpose of viewing analog TV signals, see attached image.
Then Tektronix came out with the VM700, one of the first all-digital waveform monitor.

Ever since I first used the VM700 in perhaps 1995, I have never again used an analog scope.

We used waveform monitors for convenience, but never had any major dramas with triggering Tektronix CROs ----a bit fiddly, but you could usually see individual lines OK.

I must admit, I did cheat a bit from time to time by using a device called a "Link 330", which was primarily designed for doing diff gain/phase testing, but had a very nice trigger on individual lines.

When the Tek & HP reps would come in to show us their latest & greatest DSOs, we would immediately try to display one or, hopefully, two fields of video signal.
This was a standard test at transmitting sites, to check for "clamp pulse break through" in the field sync group, where the keyed clampers would sometimes miss-clamp on the pre & post equalising pulses.

Inevitably, the DSO display would disintegrate into what looked like my overgrown back yard, from aliasing due to the reduction in sample rate at long time/div settings.

That put my employers & me, personally, off DSOs for some time!
We did have a Tek THS 720A, which was reasonable for service work on Picture Monitors & the like, but if a beat up old analog was available, I used that instead.

Was the VM700 monitor the one with the touch screen?

We had a waveform monitor with such a screen, & I was trying to point out a "glitch" on blanking level to another Tech, so touched the screen where it was, as you normally do with  conventional units, & the $&&$$/-/&)))!!! thing changed ranges!

I ran into a few DSOs in later jobs, but usually they weren't the newest devices, & there was aways an analog 'scope available as well, which I used due to familiarity & known performance.

Now I'm retired, I can't afford to buy a modern DSO anyway, & my Tek 7613 does all I need it to do.
Surprisingly, the analog storage function is quite good on this one, & if I really want a permanent record of a
waveform, a digital camera does the job.
 

Offline Mr. Scram

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #72 on: August 03, 2019, 03:59:42 am »
Another thing I like about analog CROs: control inputs are immediate, and tactile. I get to spend time with two expensive digital scopes at work...I have a Tek TDS5k series 1 GHz DPO on my desk and there's a Keysight MSO-X 6k down in the lab. While both are amazingly capable, I absolutely despise having to navigate menus to find functions.  :wtf: Plus, control inputs have an annoying amount of latency between input and effect.
That's strange as Keysight's Megazoom oscilloscopes are famed for their immediate hardware accelerated response to inputs and not slowing down when more features are enabled. Does the 6K series run an additional "desktop" Windows layer?
 

Offline 0culus

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #73 on: August 03, 2019, 04:07:04 am »
Another thing I like about analog CROs: control inputs are immediate, and tactile. I get to spend time with two expensive digital scopes at work...I have a Tek TDS5k series 1 GHz DPO on my desk and there's a Keysight MSO-X 6k down in the lab. While both are amazingly capable, I absolutely despise having to navigate menus to find functions.  :wtf: Plus, control inputs have an annoying amount of latency between input and effect.
That's strange as Keysight's Megazoom oscilloscopes are famed for their immediate hardware accelerated response to inputs and not slowing down when more features are enabled. Does the 6K series run an additional "desktop" Windows layer?
I don't think it does; when it boots there is zero sign of windows. It absolutely is faster at responding to inputs than the DPO, which runs windows 2k.  :-DD But I can still feel that it's just not quite as immediate as my analog 'scopes at home. IMO, YMMV.  :-+
 

Online rsjsouza

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Re: Do You still use analog oscilloscopes in 2019?
« Reply #74 on: August 03, 2019, 08:29:18 am »
Another thing I like about analog CROs: control inputs are immediate, and tactile. I get to spend time with two expensive digital scopes at work...I have a Tek TDS5k series 1 GHz DPO on my desk and there's a Keysight MSO-X 6k down in the lab. While both are amazingly capable, I absolutely despise having to navigate menus to find functions.  :wtf: Plus, control inputs have an annoying amount of latency between input and effect.
That's strange as Keysight's Megazoom oscilloscopes are famed for their immediate hardware accelerated response to inputs and not slowing down when more features are enabled. Does the 6K series run an additional "desktop" Windows layer?
I don't think it does; when it boots there is zero sign of windows. It absolutely is faster at responding to inputs than the DPO, which runs windows 2k.  :-DD But I can still feel that it's just not quite as immediate as my analog 'scopes at home. IMO, YMMV.  :-+
At work I used to use both a TDS7104 (Win2k) and a TDS3054B and they were very slow, with an edge for the 3054.

My Rigol DS4014 runs circles around these in this aspect.
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