Analog  scope - Page 1
Forum section: electronics / beginners

author: Bob K
author_rank: Newbie
timestamp: November 01, 2015, 04:05:04 am
content: Is it necessary to have an analog scope.I have 2 digital scopes will that be sufficent

author: crispy_tofu
author_rank: Super Contributor
timestamp: November 01, 2015, 04:12:51 am
content: I wouldn't say that it's necessary...

author: retrolefty
author_rank: Super Contributor
timestamp: November 01, 2015, 06:29:40 am
content: Quote from: Bob K on November 01, 2015, 04:05:04 amSure you do, it's more for the street cred then it's capability.

author: tggzzz
author_rank: Super Contributor
timestamp: November 01, 2015, 09:55:05 am
content: Quote from: Bob K on November 01, 2015, 04:05:04 amI suspect you forgot to finish the last sentence, but in the absence of that...No, they won't be sufficient to hold down a tent in a high wind.If you have some other purpose in mind for them, then they might or might not be sufficientdepending on the purpose.Short answer: sufficientfor what?

author: Zero999
author_rank: Super Contributor
timestamp: November 01, 2015, 10:58:26 am
content: Quote from: Bob K on November 01, 2015, 04:05:04 amThat depends on the digital 'scopes you already have and what analogue 'scope you intend to buy.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 01, 2015, 11:23:55 am
content: "Digital 'scope" can mean anything.I would say if you have a new Rigol DS1054Z or a new-ish Agilent,&a "hacked" Rigol DS1052E,you are good to go---but if what you have are very old,very small or very USB,it wouldn't hurt to have an analog one.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: November 01, 2015, 04:29:44 pm
content: Do you want to display "Oscillofun" or other X-Y mode graphics? Then you probably need an analog scope, unless one of your DSOs is a high-end high performance model.https://www.youtube.com/channel/UCECl4aNz5hvuRzW5fgCOHKQ

author: dom0
author_rank: Super Contributor
timestamp: November 01, 2015, 11:56:22 pm
content: I am certain that this question was neither brought up nor discussed in entirety before.

author: nbritton
author_rank: Frequent Contributor
timestamp: November 02, 2015, 12:24:21 am
content: Quote from: alsetalokin4017 on November 01, 2015, 04:29:44 pm

author: nbritton
author_rank: Frequent Contributor
timestamp: November 02, 2015, 12:44:13 am
content: If your DSO has an intensity gradient display then no I don't believe you need an analog scope. I'm not sure of their reasoning, but I've noticed that many people have a nostalgic attachment to old, and often totally obsolete, test equipment.

author: GreyWoolfe
author_rank: Unknown
timestamp: November 02, 2015, 03:15:12 am
content: I have a hacked Hantek DSO5102B but I also have a Tektronics 2235 that I have my octopus circuit tester connected to. Plus it's there for when the granddaughter wants me to play with Lissajous patterns.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 02, 2015, 03:19:46 am
content: Many people were "bitten" by early generation DSOs which,although useful in many situations,were totally unsuitable as general purpose workshop instruments.Back in the early 1990s Tektronix & HP Reps would come to my then work to demonstrate the "latest & greatest" DSOs.They would be all primed up to argue the benefits of vector and/or dot displays,& various other exotica,& totally overawe the Old Fogeys.Us "old fogeys" (ranging at the time from the early twenties to the mid fifties) would listen,then ask them to display some everyday signals found in a TV Studio.They failed miserably------lack of memory depth caused reduced sampling rates at longer time/div settings,so any frequencies higher than the sample rate would be totally mangled.The first couple of iterations couldn't even resolve a PAL colour burst when the timebase was set to TV line rate.They got better,but not much,until the last one which was in a cabinet like a kid's lunchboxcoulddisplay a field rate signal fairly well,but there was still some kind of aliasing going on with the colour information.It was usable,though.I never heard anyone call for a intensity graded display to make it look like a "pretend analog"---we would have been happy if it just displayed what it was looking at,even if it did look like something drawn on the back of an envelope with a leaky fountain pen!*And the UI on those old DSOs!Bland beige keyboarded front panels ,yuk!---At least the "lunchbox" one was colourful!As DSOs have improved,they have more & more converged upon an "Analog " look!No keyboards,"pretend phosphor" & the lot----the "experts back then told us that the "Vic-20"*look was the way to go!Modern DSOs can do a lot of stuff & don't have many of the limitations of the old ones,but there are still "great pretenders" around.They look much the same as better quality ones,but are not a lot better than the 1990s ones from the Big Two!One thing about old Analogs---unless they are faulty,what you see,you get!Unless you have arealneed for a DSO,they will do all normal workshop stuff & continue doing it almost indefinitely.*Sorry kiddywinks,if you don't get the references---you might have to wake a "Greybeardfrom their "Nanna Nap" to get an explanation!

author: tggzzz
author_rank: Super Contributor
timestamp: November 02, 2015, 09:02:17 am
content: Quote from: vk6zgo on November 02, 2015, 03:19:46 amMany correct points snipped for brevity.QuoteAnd that is a key point. I've seen too many beginners fall into too many traps with digital scopes. They are great for some things, but can easily give you false confidence that you've seen everything there is to see in a signal.QuoteAnd that is another key point. Analogue scopes are usually sufficient.There's one other point that is important for beginners. Digitising scopes often have too important controls hidden two deep in menu/softbutton systems. If you are expert, you will know what you need and can go and hunt for it - but a beginner won't realise what controls are there and won't realise their significance.Analogue scopes are simpler and all controls are visible on the front panel. That encourages experimentation and gives confidence that all controls have been found and their effect understood.

author: oldway
author_rank: Super Contributor
timestamp: November 02, 2015, 10:49:34 am
content: If you buy an analog scope, buy a good one.100Mhz and above are generally "industrial grade" and 20 Mhz are "hobbiest grade".Go for an "industrial grade" one.

author: tggzzz
author_rank: Super Contributor
timestamp: November 02, 2015, 12:05:44 pm
content: Quote from: oldway on November 02, 2015, 10:49:34 amThe 20MHz scopes are difficult to get rid of, and can probably be found free.Not much call for debugging analogue TVs anymore100MHz is the minimum bandwidth required for TTL signals. (If using a digital scope, ignore the S/s number beloved of salesmen.)

author: newbrain
author_rank: Super Contributor
timestamp: November 02, 2015, 08:06:58 pm
content: Quote from: Bob K on November 01, 2015, 04:05:04 amIt's a pity the OP seems to have abandoned the thread.He absolutely needs an analog scope, and, I'm willing to donate mine, if he just comes along to pick it up at my parents'.I don't have any self shot pictures, but I found this one on flickr:https://www.flickr.com/photos/keithgreenhalgh/15775018040Mine is actually branded Fairchild, not Dumont, and has a blue background CRT.It is working perfectly or at least it was last time I switched it on...about 30 years ago.It's a25kg or so beast and would make quite a show on any bench (I remember having to reinforce mine, though).Bandwidth is some tens of kHz, but with a lot of attenuation, I was able to see the 1MHz clock of my 6502 SBC.Note the differential Y input, and the large Ballast (5th picture) for filament stabilization (it took a good 10 minutes before it was usable!).Definitely, my new DS10541104Z hasn't got the same warm and fuzzy feeling...

author: Alex Nikitin
author_rank: Super Contributor
timestamp: November 03, 2015, 09:41:24 pm
content: Quote from: nbritton on November 02, 2015, 12:44:13 amThere is one particular reason why I prefer a good analogue scope over a digital one, on top of WYSIWYG, obviously. When you touch a point in a circuit with a probe, an analogue scope responds instantaneously and every digital scope I've tried (quite a few, actually) always delays the response on the screen. Not a lot of a delay, but very annoying and makes a job considerably more difficult for me. YMMV. I generally use a digital scope if I need to a) record a screen shot and b) catch a single or a very slow event. In all other situations an analogue one works better for me.CheersAlex

author: Howardlong
author_rank: Super Contributor
timestamp: November 03, 2015, 11:44:57 pm
content: Quote from: Alex Nikitin on November 03, 2015, 09:41:24 pmI do agree regarding the responsiveness of CROs.I think the real turning point for me from daily die hard CRO use over to DSO was using the Agilent 54642D, 500MHz 2Gsa/s version of the Dave Fave 54622D, and a fairly recent acquisition (see what I did there?). This was solely down to the UI and decent screen resolution. Right from the super fast five second boot up to the super intuitive and blindingly fast user interface, I found I'd pretty much switched within a week from CRO to DSO as my go to scope.I've had plenty of DSOs, many more modern and more capable on paper than the 54642D, but none had the immediacy of the Agilent. Since then I bought an Agilent 7000 series, mostly because I knew the UI was going to still be the business with the same VxWorks heritage, and it is. I do still use a CRO, the 2467B, but it's less and less. It's not even on the bench, it's on the floor under the bench, but ready to go at a moment's notice: unlike today's lunchbox scopes, the oldies work just great on the floor and take zero bench space.