Is there any need for a Analog scope on a Hobbyist's bench anymore. - Page 1
Forum section: electronics / testgear

author: Bryan
author_rank: Frequent Contributor
timestamp: November 16, 2016, 10:27:38 am
content: Over the years have managed to acquire a number of analog scopes a old BK, Tek 2215, and a assortment of Tek 2465 scopes. Yes I know they can be addictive. Nothing like watching the relays click, the lights on the front panel and the nice warm glow of the CRT. But I have not used any in over a year, other than just show a few friends that these scopes cost more than car in the day, suppose that still holds true for some of the digital scopes today <g> . Seems about five years ago when Rigol introduced the then revolutionary DS1052E to the hobbyist the pace of evolving digital scopes has been amazing and was a turning point, certainly at the hobbyist level. I just picked up a Siglent scope and it is for my purposes quite amazing for the price point.I suspect in a couple years that the entry level digital scope is going to be well over 200Mhz with loads of features that used to be only available on more expensive models. So this begs the question, as a hobbyist why do we need a analog scope any longer. I suppose for high frequency RF work, but other than that I just don't see any point any longer. I notice that a few U-Tube contributors who no longer use their analog scopes any longer in their videos. Guess it's the end of a era.So do you see a need for analog scope any longer?

author: nfmax
author_rank: Super Contributor
timestamp: November 16, 2016, 10:29:33 am
content: No

author: AndyC_772
author_rank: Super Contributor
timestamp: November 16, 2016, 10:32:20 am
content: No

author: tggzzz
author_rank: Super Contributor
timestamp: November 16, 2016, 10:39:01 am
content: Quote from: Bryan on November 16, 2016, 10:27:38 amNeed: no, except in some unusual circumstances.What I object to is people claiming that analogue scopes are useless, especially in conversationswith beginners that can't afford a new digital scopeclaiming that 50/100MHz is sufficient for verifying that modern "digital" signals arevaliddigital signals, i.e. signal integrityWith a little bit of imagination and understanding, analogue scopes can be used for many many purposes. You can't buy imagination and understanding, but you can buy a digital scope.

author: coppice
author_rank: Super Contributor
timestamp: November 16, 2016, 10:43:49 am
content: If there were a solid need for analogue scopes the major scope makers would still be making them.

author: H.O
author_rank: Frequent Contributor
timestamp: November 16, 2016, 11:20:37 am
content: I just moved my Tektronix 2465B from my main bench to a storage shelf. It's been sitting next to my Rigol DS4000 without being used for well over a year now and very rarely having been powered on since I recapped the power supply years ago. Basically the only time I've used since then was to compare the bandwidth of the upgraded DS4k to a "known good" 400MHz scope. The comparison showed I no longer have a need for the 400MHz bandwidth (as if I had before....) :-)I'm seriously considering selling it but I don't think it'll fetch enough money to be worth the trouble.If your main interest is digital stuff, microcontrollers, serial protocols and so on then a DSO is just so much more useful than an analog scope.

author: Bryan
author_rank: Frequent Contributor
timestamp: November 16, 2016, 11:33:55 am
content: Quote from: H.O on November 16, 2016, 11:20:37 amSame here, will probably get rid of them all except for one, and only keep it as a memento of the past<g> Seems the Tek 2456(a/b) still seem to go for a pretty penny on Ebay. So somebody still wants them.

author: JPortici
author_rank: Super Contributor
timestamp: November 16, 2016, 11:41:29 am
content: Quote from: tggzzz on November 16, 2016, 10:39:01 am+1 on thaton a cheapass tektronix mainframe i can look at signals that are much higher in frequency than with a cheapass DSOon said cheapass tektronix mainframe i can put a 7A22 plugin and do very low noise measurements well below the noise floor of said cheapass DSOboth are niches case i suppose.

author: EEVblog
author_rank: Unknown
timestamp: November 16, 2016, 11:47:06 am
content: Quote from: Bryan on November 16, 2016, 10:27:38 amYou don't.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: November 16, 2016, 11:54:33 am
content: Horses for courses I suppose. At my home lab I have four scopes - three analogue Teks, two of which are used regularly, one kept as a spare, and one DSO, used very rarely. At work I have several DSOs, used regularly, and one analogue scope, used occasionally, when I need to troubleshoot an analogue/RF/HV stages. Majority of what I do is analogue and RF though.CheersAlex

author: bktemp
author_rank: Super Contributor
timestamp: November 16, 2016, 12:00:43 pm
content: For some applications analogue scopes are still usefull:The XY mode on most low end DSO sucks. You don't need it often, but when you need it, nothing beats having an analogue scope with a true XY mode.Also displaying modulated waveforms is much better on analogue scopes, because they have no aliasing problems.I rarely use my analogue scope, but occasionally it has some benefits. For most use cases, todays DSOs are much better than analogue scopes.

author: chris_leyson
author_rank: Super Contributor
timestamp: November 16, 2016, 12:14:30 pm
content: Probably not these days but sometimes they are useful. I've got two digital scopes both of them are under sampling so they are only good for repetitive signals and no good for transients. The other day I was looking at brushed DC motor current and commutator voltage spikes for a sensorless rotation counter, the under sampling digital scopes were useless and I had to use a 7854 in analogue mode. If I had a decent digital scope I wouldn't need to resort to using my analogue antiques.

author: Fenichel
author_rank: Contributor
timestamp: November 16, 2016, 01:01:42 pm
content: Quote from: bktemp on November 16, 2016, 12:00:43 pm+1For some examples of XY views that I couldn't obtain on my Rigol 1054, seehttp://www.fenichel.net/pages/Indoor_Activities/electronics/chaos/chaos.htm

author: JLNY
author_rank: Regular Contributor
timestamp: November 16, 2016, 01:25:42 pm
content: For the serious hobbyist who already has a scope? No.For the beginner who is only going to be able to afford a used scope? Yes.As far as I'm concerned, the main advantage that most digital scopes have over analog ones is the ability to store one-time signals. Aside from that, I can only think of a few applications where an analog scope wouldn't be comparable or better. As mentioned above, a decent used CRO will have lower noise than a cheap DSO in most cases.It also depends on what types of projects a hobbyist plans to work on. Most hobbyists these days seem to go for digital projects like microcontrollers, so it probably makes sense to get a DSO if you can afford one. That said, for someone like me who is mainly into audio and RF applications, I probably still use my analog scope more than my DSO.

author: Fungus
author_rank: Super Contributor
timestamp: November 16, 2016, 01:26:57 pm
content: No.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 16, 2016, 02:20:23 pm
content: Quote from: Bryan on November 16, 2016, 10:27:38 amNo, really not.Quote from: JLNY on November 16, 2016, 01:25:42 pmMaybe if you're completely broke and need a scope, and you can get one fully working for free or a few bucks (i.e. <$50, as around $100 you can already get a decent DSO like the HP 54622A/D), if you want to play with antique test gear or if you work in audiophoolery where you don't want to be caught out being seen using something digital, but other than that don't waste time with analog boat anchors and learning obsolete probing techniques.QuoteIn general no, not really (unless you pick one of the high end scopes with low noise plugin), you just don't see the noise in the bloom of the CRT. Like a lot of other stuff that easily can get hidden from the user in an analog scope.

author: Fungus
author_rank: Super Contributor
timestamp: November 16, 2016, 02:23:36 pm
content: Quote from: JLNY on November 16, 2016, 01:25:42 pmBut only of you can get it for, like, $50 or less.(unless it's some exceptional high-end model with amazing bandwidth and features, in which case you can go up to $100)

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 03:01:36 pm
content: Quote from: tggzzz on November 16, 2016, 10:39:01 amAnd these are usually my first justifications although I could add a couple more:1. If it means the difference between an oscilloscope and no oscilloscope, then an analog oscilloscope is far better than nothing.2. If maximum bandwidth is required within a budget, then an analog oscilloscope is better. No features make up for lack of bandwidth. (*)Beyond that there are more specialized considerations like:3. DSO XY mode is terrible compared to an analog oscilloscope. It does not have to be but it is at least in all of the ones I have seen including mine.4. Some analog oscilloscope have special input capabilities like high common mode and high sensitivity differential inputs. Adding these onto a budget DSO will cost more than the DSO, maybe a lot more.(*) I am becoming more suspicious that oscilloscopes like the Rigol 1000Z series suffer from overload problems even within their input voltage range meaning that they do not achieve even their rated bandwidth without distortion in their transient response. But most users who would notice this would be using a faster and more suitable oscilloscope anyway.

author: retrolefty
author_rank: Super Contributor
timestamp: November 16, 2016, 03:10:05 pm
content: Quote from: blueskull on November 16, 2016, 11:29:42 amWell I've never owned a Digital Scope, and I do everything (I need) with a 2213.I of course have nothing against modern digital scopes and I probably might even buy one intime.

author: JLNY
author_rank: Regular Contributor
timestamp: November 16, 2016, 03:24:17 pm
content: Quote from: Wuerstchenhund on November 16, 2016, 02:20:23 pmFair point, and perhaps I am running off of somewhat dated information. An increasing number of older DSOs like the HP 54XXX and Tek TDS lines are now finding their way into the hobbyist market and are rapidly becoming affordable to the beginner. Perhaps I should revise my statement to simply say that beginners shouldn't discount the idea of getting used scopes rather than dropping several hundred right away on a brand new one. I have nothing against DSOs, and certainly when I do digital work I almost always use a DSO. But I almost always go for used equipment when I can, mostly due to cost.

author: tggzzz
author_rank: Super Contributor
timestamp: November 16, 2016, 03:31:18 pm
content: Quote from: David Hess on November 16, 2016, 03:01:36 pmAgreed.Undermy"unusual circumstances", I'd add5. sensitivity for low bandwidth signals (but I'd want to check what's available before being dogmatic about that)6. recovery from overload conditions, e.g. if you are looking at settling times. However most analogue scopes are poor in that respect as well; some say analogue sampling heads are best, since they "ignore" the signal except during sampling.7. misleading waveform "reconstructions" with first/second order holds, rather than just points indicating what is actually known8. as others have noted, for amplitude modulated waveforms, or where non-obvious subsampling can mislead the unwary.QuoteShades of the old "transient intermodulation distortion" that was contentious in audio circles a few decades ago? (TIM is, roughly speaking, caused by slew-rate limiting).Or maybe an internal node in a diff amp saturating?As I implied, I find rabid fan-boy "X is better" statements distressing, although not surprising.I'm perfectly happy with "X is better, except when Y" statements, and positively like "X is better except when Y, but Z is often sufficient" statements.

author: tggzzz
author_rank: Super Contributor
timestamp: November 16, 2016, 03:41:38 pm
content: Quote from: JLNY on November 16, 2016, 03:24:17 pmFor a beginner, any secondhand equipment has to be fully working; no surprises there. For me, any secondhand equipment has to be fully working or repairable. The Agilent 54XXX and Tek TDSs are less repairable and less capable than similarly priced Tek/HP analogue scopes (and short capture buffers aren't helpful).Personally I seriously dislike the TDS320 available to me, and while the Agilent 54621 is nicer to use, I find its 60MHz bandwidth unacceptable. (Hell's teeth, even in the70s60MHz wasn't adequate and 100MHz was the minimum acceptable!)My preference, as an amateur: a working >=300MHz analogue scope for everyday use, a 10MHz digitising scope for transients (and maybe capturing SPI etc), plus understanding and imagination.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 16, 2016, 04:31:18 pm
content: Quote from: JLNY on November 16, 2016, 03:24:17 pmPersonally I now only buy 2nd hand gear (after a few attempst with Chinese B-brand kit), simply because you can get some great and not that old instruments for reasonable money.Quote from: tggzzz on November 16, 2016, 03:41:38 pmEspecially the 54600 Series has shown to be really reliable (the only weak point is the mains filter, as on many old instruments). They simply lack the amount pots, trimmers and mechanical switches that are prevailent in most analog scopes and which after decades are prime points of failure. It's also less susceptible to the effects of component ageing.And as to repairability, there are enough proprietary components in a lot of analog scopes that today are pretty much unobtainium.As to less capable, I don't think so. Even a HP 54622 comes with various automatic measurements, simple FFT (via expansion module), and in the 'D' (MSO) variant even a logic analyzer, above basic things like storage and zoom. These scopes also have HP's fast MegaZoom ASIC with 2Mpts memory so there's more than enough memory as well as high waveform update rates.The old Tek TDS scopes are a different story, though, not only are even very old ones regularly more expensive than a comparable HP DSO, many suffer from the capacitor plague and need a complete re-cap which isn't something I'd put on a beginner. The old ones (TDS3xx) are also very slow, and the later ones are only fast in a special high waveform mode which reduces the dataQuoteI agree, but even a 54622D (100MHz MSO) isn't really any more expensive today, and quite often you can even find a 54641A (350Mhz) or 54642A (500Mhz) variant for decent money.My preference, as an amateur: a working >=300MHz analogue scope for everyday use, a 10MHz digitising scope for transients (and maybe capturing SPI etc), plus understanding and imagination.

author: tggzzz
author_rank: Super Contributor
timestamp: November 16, 2016, 04:59:02 pm
content: Quote from: Wuerstchenhund on November 16, 2016, 04:31:18 pmThat's what I choose to afford, as wellQuoteFair points, with one exception: where are the soft calibration constants stored.In some ways I prefer tweaking a few pots to trying to replace a batteryinsidea large IC soldered to a PCB (Tek, I'm thinking of you)Or even performing gymnastics to desolder (=> cannot be connected to the mains) and replace a lithium battery without the ordinary static RAM becoming unpowered and losing its contents (HP, I'm thinking of you).QuoteYou do have to choose your equipment carefullyReady availability of donor scopes is a good starting point, and it feels like some working scopes are being commercially broken up for their components.QuoteI was thinking of capability in terms of raw bandwidth. Without that, all the "fancy post processing" is merely a marketeer's wet dreamQuoteA quick skim of fleabay shows a broken 54642A for £524, and a working one for £1700. Not cheap by my standards.I've sold a not-quite-perfect 350MHz 485 for <£200, and it might have reappeared on fleabay for >£250.

author: chris_leyson
author_rank: Super Contributor
timestamp: November 16, 2016, 05:01:02 pm
content: I agree the HP 54600 series scopes are good value or money these days. I have a 54610 which just happens to have 700MHz bandwidth (derived from rise time measurement) but it is an under sampler sampling at 20MHz so it won't catch fast transients and that's why I had to resort to using an analogue scope to see the transients, a proper over sampling digital scope would have caught them.

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 05:02:20 pm
content: Quote from: tggzzz on November 16, 2016, 03:31:18 pmThat is basically what it comes down to because noise increases with bandwidth. Differential inputs can sometimes help reduce noise although this is one place where modern DSOs are terrible because the quantization noise gets added when used differentially (but not with high resolution mode?); some old DSOs did this in the analog domain so do not suffer from this.Of course modern DSOs have averaging and high resolution mode available which helps a lot. Averaging requires a stable trigger and repetitive waveform though.QuoteIt varies a lot between oscilloscope models but I have never seen a DSO with "fast overload recovery" as a specified feature. Some analog oscilloscopes include it though.Properly working sampling oscilloscopes ignore non-destructive overload.QuoteGibbs phenomenonreally bugs me but all of my DSOs support equivalent time sampling so it is usually not an issue. It especially bugs me when the 20 MHz analog bandwidth limit does not have it but the 20 MHz DSP bandwidth limit does and the manufacturer's application engineers cannot explain it. (There is an explanation for the difference and why but it is too long to include here.)QuoteWe were discussing a couple examples in a Rigol 1000Z discussion here a couple weeks ago which I originally thought were problems with transient response but after further consideration, I think something else was going on. The waveforms actually looked more like overload recovery so I now suspect something like slew rate limiting in a feedback amplifier or inadequate tail current in a differential amplifier.

author: bson
author_rank: Unknown
timestamp: November 16, 2016, 05:06:27 pm
content: No gets my vote too.From a purely practical perspective: old analog scopes are huge and I can think of better use of bench space... so unless it tickles something inside you or you're saving coin for an entry-level DSO, don't bother.

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 05:20:02 pm
content: Quote from: Wuerstchenhund on November 16, 2016, 04:31:18 pmThe capacitor problems, lack of full documentation, and loss of calibration if the non-volatile memory contents was lost convinced me to stay away from the Tektronix TDS series. The color LCD shutters all seem to have failed by now as well.

author: mtdoc
author_rank: Super Contributor
timestamp: November 16, 2016, 05:28:04 pm
content: Not needed but fun! After all that's what a hobby should be about.Some of us still enjoy the beauty and quirks of using an analog scope - even when we have a modern DSO sitting on our bench next to it.

author: bson
author_rank: Unknown
timestamp: November 16, 2016, 05:53:53 pm
content: Quote from: mtdoc on November 16, 2016, 05:28:04 pmDepends on what your hobby is! To me, making progress on designs and getting things to work is fun, trying to debug transient problems with an analog scope doesn't qualify as fun in my book...

author: tggzzz
author_rank: Super Contributor
timestamp: November 16, 2016, 06:03:16 pm
content: Quote from: bson on November 16, 2016, 05:06:27 pmWhile there is some truth in that, "huge" is an exaggeration. Someveryusable classic scopes were designed to fitunderaircraft seats.

author: mtdoc
author_rank: Super Contributor
timestamp: November 16, 2016, 06:06:02 pm
content: Quote from: bson on November 16, 2016, 05:53:53 pmWell sure, of course as has been pointed out endlessly on this forum, there are many things that a DSO does that an analog scope can't do or does poorly. Choose the right tool for the job, etc, etc. No need toBut.. many, if not most, of the things the average hobbyist does could be done with an analog scope - as was done for decades.I have a very nice Rigol scope on my bench. But more often than not the task at hand can be accomplished with one of my analog scopes - and I find myself usually reaching for the analog scope just because - well - it's fun and it gives me a warm fuzzy feeling that using a digital scope doesn't.

author: Fungus
author_rank: Super Contributor
timestamp: November 16, 2016, 06:11:29 pm
content: Quote from: tggzzz on November 16, 2016, 04:59:02 pmThat's fine if you're living in a room crammed with other 'scopes and lots of spare parts to repair the old second-hand analog 'scope with.If you're a newbie who only has a multimeter and a couple of Arduino starter kits on his bench? Not so much.$200 bucks for a 'classic' oscilloscope is still a lot of money if it has problems after a few weeks and you have no experience and nothing else to diagnose it with.Quote from: mtdoc on November 16, 2016, 06:06:02 pmTrue... but not for everybody.Quote from: mtdoc on November 16, 2016, 06:06:02 pmIt's nice to be able to choose. If you could only keep one of them though, which would it be?Quote from: mtdoc on November 16, 2016, 06:06:02 pmNobody's denying old analog 'scopes are cool and fun to use.

author: tggzzz
author_rank: Super Contributor
timestamp: November 16, 2016, 06:15:46 pm
content: Quote from: bson on November 16, 2016, 05:53:53 pmTransient problems are always a pain, in hardware, software, life...The first step todemonstratingthat you havesolvedthem is to make them repetitive. If you can't do that then, arguably, you have merely not seen them againAnd, of course, if they are repetitive, then an analogue scope is sufficient. (Yes, I know that's an outrageous exaggeration, but thereismore than a grain of truth in it).

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 16, 2016, 07:41:02 pm
content: Quote from: tggzzz on November 16, 2016, 06:15:46 pmYes, but at least in electronics with the right tools the pain level drops notably. With a decent DSO capturing transiients isn't a problem, even those that on an analog scope might not even show due to insufficient brightness or because it gets lost in the gloom. It's pretty easy with a good trigger and analysis suite, and if the wanted signal is repetitive then even a basic DSO does the job with persistence mode or mask testing.QuoteYes, if you made the transients repetitive or determined their occurrence parameters, which usually means you already need to know where the problem is. Which isn't much help for finding the problem in the first place.

author: tautech
author_rank: Super Contributor
timestamp: November 16, 2016, 08:06:26 pm
content: Quote from: Bryan on November 16, 2016, 10:27:38 amSounds a bit like my bench.....numerous old CRO's in various states of repair and lack of motivation to fix them AND keep them operative, but maybe one day.Is this new Siglent your first DSO ?When I got my first, a Tek TDS2012B it opened my eyes to the future and from that day on CRO's became less of a focus (pun intended) for me. I still like a lovely fine trace on therightphosphor when they're working andcorrectly but as others have pointed out you can spend considerable time keeping these old girls going. And that's not novice territory.QuoteNo.I've never found a need to get one out since I've had a DSO.But there are CRO classics, just like Model A's and T's they have stood the test of time and will be continue to be used by some for a good few years yet. I admire those that put the effort into restoring these old beauties even though in good time they'll only be museum pieces.Don't think I'd want to use one as my "daily driver" though.

author: DimitriP
author_rank: Super Contributor
timestamp: November 16, 2016, 08:14:12 pm
content: For hobbyists, "need" is more of an excuse, than a reason.Just like 40-60 piece precision screwdriver sets on a $50 stand , or $300 DMMs.So the answer depends on the hobbyist, not on the type of equipment.

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 08:15:28 pm
content: Quote from: Fungus on November 16, 2016, 06:11:29 pmIf I could only keep one?Then it would be a Tektronix 7834 or 7934 so I get storage, variable persistence, wide bandwidth, instant overload recovery, differential comparator inputs, 4 traces, dual dual delayed sweep, delta delayed sweep, alternate sweep, 10uV/div sensitivity, and mixed domain (pick two of frequency, logic, real time, sampling, and curve trace) operation.And it can crush zombies also.My second choice if a had a very limited budget would be a Tektronix 2230/2232 with the later preferred of course but the former is acceptable.

author: tautech
author_rank: Super Contributor
timestamp: November 16, 2016, 08:21:29 pm
content: Quote from: David Hess on November 16, 2016, 08:15:28 pmWhich begs another question:Which classic CRO is best to hang onto?New thread ?

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 08:40:19 pm
content: Quote from: tautech on November 16, 2016, 08:21:29 pmThat is pretty easy with a brief answer though; keep the one which provides needed capability which would otherwise be unaffordable. That will usually be bandwidth but it might be sensitivity or sampling capability.

author: tautech
author_rank: Super Contributor
timestamp: November 16, 2016, 08:58:11 pm
content: Quote from: David Hess on November 16, 2016, 08:40:19 pmOr zombie crushing ability.The old Tek 500's come to mind....

author: nctnico
author_rank: Super Contributor
timestamp: November 16, 2016, 09:06:45 pm
content: Quote from: tautech on November 16, 2016, 08:21:29 pmWhat counts as classic? The last CRO I owned was a 4 channel 470MHz Iwatsu SS7847-A (rebadged as a Lecroy LA314H) which IIRC wasn't bad because it was relatively new. However I liked the Tektronix TDS510A which replaced it much better.

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 09:07:16 pm
content: Quote from: tautech on November 16, 2016, 08:58:11 pmI have a pair of those also although they do not offer any unique capabilities except for spot size on the 547.

author: tautech
author_rank: Super Contributor
timestamp: November 16, 2016, 09:27:18 pm
content: Quote from: nctnico on November 16, 2016, 09:06:45 pmAnalog.

author: Bryan
author_rank: Frequent Contributor
timestamp: November 16, 2016, 09:43:51 pm
content: Quote from: JLNY on November 16, 2016, 01:25:42 pmDavey J did a video on that and not entirely true.https://youtu.be/Znwp0pK8Tzk

author: tautech
author_rank: Super Contributor
timestamp: November 16, 2016, 09:52:49 pm
content: Quote from: Bryan on November 16, 2016, 09:43:51 pmAnd Pt. 2https://www.eevblog.com/2014/04/27/eevblog-610-why-digital-scopes-appear-noisy-part-2/

author: Bicurico
author_rank: Super Contributor
timestamp: November 16, 2016, 10:11:38 pm
content: CRT scope is nice for nostalgic moments and especially if you use them to render games like Asteroids...https://github.com/joemck/oscilloscope-asteroidsOr:-> Dave has compared this one between CRT and DSO:Or:-> The same on a Rigol DS1054Z:Regards:Vitor

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 11:46:25 pm
content: Quote from: Bryan on November 16, 2016, 09:43:51 pmI do not really disagree with Dave on this subject but his videos would have been more convincing had he quantitatively measured the noise.

author: David Hess
author_rank: Super Contributor
timestamp: November 16, 2016, 11:55:22 pm
content: Quote from: Bicurico on November 16, 2016, 10:11:38 pmThey are also nostalgic for checking the performance of your reference level pulse generator and incidentally revealing that your TTL pretrigger delay design is completely inadequate for your pretrigger needs without spending enough for a new car.This measurement was made with a Tektronix 7834 at 14 GHz of bandwidth. The photograph was processed for easy printing by a cat.

author: edavid
author_rank: Super Contributor
timestamp: November 17, 2016, 12:35:04 am
content: Quote from: David Hess on November 16, 2016, 05:20:02 pmCertainly not true, there are plenty of good ones around:https://www.eevblog.com/forum/buysellwanted/fs-tds754d-500-mhz-scope-(mainly-uscanada)/

author: jonovid
author_rank: Super Contributor
timestamp: November 17, 2016, 12:42:33 am
content: if its about affordably . will a good 2 Channel pc based USB scope do the job? I have a old DS crt scope.love the old analogue. bit their comes a time when you need a lot more scope!

author: bson
author_rank: Unknown
timestamp: November 17, 2016, 02:06:27 am
content: Funny you should mention Asteroids, because I remember being totally fascinated by the design of its vector graphics board, which was separate from everything else in the cabinet. I don't recall if it was included standard in every unit, but somehow a group of us came by the schematics for it. (We bought the cabinet.) This was in the late 80s, so it was already out of the arcades by then. Its graphics "processor" was a very simple state machine. By all means get a naked CRT and amplifier boards and go to town designing a vector graphics system - that sounds like a really fun project. But you'd probably still want a DSO for that.And, yes, I did in fact poke and prod the original VG board with an analog scope, an inexpensive 2MHz one.

author: oldway
author_rank: Super Contributor
timestamp: November 17, 2016, 12:19:56 pm
content: I'm a fanboy of analog oscilloscopes, I will not hide it.Do you need an analog oscilloscope? No.But a good analog oscilloscope has made it possible to do a lot of work in the past and this has not been finished simply by the development of digital oscilloscopes.An analog oscilloscope is still very useful for beginners, for repair, for analog electronics and for power electronics.A greatfor digital oscilloscopes but without ignoring the usefulness of analog oscilloscopes in some fields of application.

author: carl_lab
author_rank: Frequent Contributor
timestamp: November 17, 2016, 12:58:13 pm
content: Quote from: Wuerstchenhund on November 16, 2016, 02:20:23 pmI love to play with antique test gear, so if you have a HP54622Dfor sale or find one at ebay for 100 bucks, please send me PM.

author: JLNY
author_rank: Regular Contributor
timestamp: November 17, 2016, 07:05:57 pm
content: Quote from: carl_lab on November 17, 2016, 12:58:13 pmI mean, I guess folks have different definitions of the term "antique," but I wouldn't consider the HP 54622D to be THAT old.I mean, if you wanted a *real* antique, I would send you my HP 140A, but I suspect that the shipping costs to Germany would be a tad high haha. It probably falls into the "zombie crusher" category.

author: Daruosha
author_rank: Regular Contributor
timestamp: November 17, 2016, 08:52:02 pm
content: I think an analog scope can be a great learning tool. No auto set, no single shot. Everything is manual and it forces you to really understand what's going on. With "limited" analog functionality, you'll learn to overcome difficulties and make yourself familiar with you tool.Of course that's what I'm thinking. Anyone has right to think different. :-)

author: andy2000
author_rank: Frequent Contributor
timestamp: November 18, 2016, 06:30:43 am
content: If I had to live with one, I would take a good analog scope over a bad (cheap/old) digital scope. A good digital scope can't be beat, but there are a lot of tasks you just can't do at all with a bad one. Try viewing a complex waveform like a video signal on a low end digital oscilloscope. You just end up with a screen full of aliased garbage.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 18, 2016, 06:31:42 am
content: Quote from: carl_lab on November 17, 2016, 12:58:13 pmThe antique referred to analog scopes, but anyways. You can find often find HP 54600 Series scopes for very low prices, even the 54622A/D or 54645A/D if you have some patience. Unfortunately the run-up to Xmas is when prices tend to go up so I'd wait after New Year's Eve after which prices tend to become more reasonable.

author: Bryan
author_rank: Frequent Contributor
timestamp: November 18, 2016, 07:18:53 am
content: Quote from: Bryan on November 16, 2016, 10:27:38 amI do have to mention that one of my favourite U-tube Channels Mr. Carlsons Lab uses some of the oldest test equipment around to fix and diagnose.<g>

author: alsetalokin4017
author_rank: Super Contributor
timestamp: November 18, 2016, 09:25:02 am
content: Quote from: David Hess on November 16, 2016, 03:01:36 pmI am in full agreement.

author: MrWolf
author_rank: Regular Contributor
timestamp: November 18, 2016, 11:00:23 am
content: +1 beauty of analog RF really gets lost in DSOs with firmware made by schoolkid hackers...

author: RoGeorge
author_rank: Super Contributor
timestamp: November 18, 2016, 02:08:19 pm
content: Wow, who doesn't want to be a hacker!Ontopic: Yes, but only if you don't already have other more convenient tool.My analog scope is gathering dust for a few years now, but I still keep it because it has galvanic isolation from the mains (by design).Last time I used it to look at the 230 Vac mains waveform.It is an old CI-118A, 2*20 MHz, a very basic and cheap, Russian made like the one in this clip:

author: raysantos
author_rank: Unknown
timestamp: December 03, 2016, 08:01:31 am
content: I spent the last four days searching eBay for a good used Tektronix 465b or 2465b to buy as my first scope.After reading this thread I've decided to drop the used Tek scope idea and instead get the Rigol DS1054Z.Thanks to everyone who commented on this thread before me.

author: tggzzz
author_rank: Super Contributor
timestamp: December 03, 2016, 10:22:00 am
content: Quote from: raysantos on December 03, 2016, 08:01:31 amA 465B and 2465B are very different, e.g. 100MHz vs 400MHz. So, if either are satisfactory, you could consider:many scopes "in between" the two, e.g. 475, 485, 2445 and others. Seehttp://w140.com/tekwiki/wiki/Main_Pagefor a quick overview of the options (and more)The HP1740A is equivalent to a 465 and is a delight to use - and much cheaper.Yes, I've used all of the above.Whether any of those is preferable to a DS1054Z depends on many factors, particularly your budget and what you need the scope to see. And I'm not going to rehash that argument!

author: JanNousiainen
author_rank: Contributor
timestamp: December 12, 2016, 11:11:28 am
content: Quote from: Wuerstchenhund on November 18, 2016, 06:31:42 amI already have 54621A and 54621D (got analog only model first and then later tried mixed signal model at work and found it much more suitable for my needs) but I would like to have something with more bandwidth ie. 54645A/D, not neccessarily because I need it but because it would be nice to have just in case... I have been following 500 MHz model prices in ebay for short while and they seem to be in 1500 - 1000€ bracket. Do you have guesstimate what is reasonable price for working 500 MHz models?These are great scopes, user interface just works. I have tinkered a bit with first gen Infinium scopes and they do not feel nearly as good...

author: rstofer
author_rank: Super Contributor
timestamp: December 12, 2016, 04:13:50 pm
content: Quote from: RoGeorge on November 18, 2016, 02:08:19 pmI always wanted to be a hacker but my parent's house didn't have a basement. Everybody knows that the best hacking comes from basements!So, I have the DS1054Z and a Tek 485. Suppose I could choose only one, which would I keep? The DSO has an abundance of features, I haven't begun to explore then all. The single shot mode alone is worth a lot. OTOH, the 485 has a lot of bandwidth and none of the idiosyncrasies of the DSO. What you see is pretty much what was there. Not withstanding a lack of persistence...Tough choice! I would tend to dump the DSO for the analog but the analog is really old. I wonder how much longer it will be around? OTOH, I am really old. How long does the scope need to last?There is certainly nothing wrong with an analog scope. My main concern is whether the units from eBay work. There is at least one forum user who didn't come out well buying a used scope. Or even two scopes. I got lucky, my 485 works fine.

author: tggzzz
author_rank: Super Contributor
timestamp: December 12, 2016, 05:25:57 pm
content: Quote from: rstofer on December 12, 2016, 04:13:50 pmThat's all a rational summary (i.e. I have the same views). Anyone that says a 1054 is better than a 485,or vice versa, is a twit, pure and simple. OTOH if they say "better for X", then they may well be right.You should, of course, use the right tool for the job, and be aware of different tools' strengths and weaknesses. That's why I bought an Analog Discovery for the full non-academic price: it is a usefulcomplementto my everyday scopes (a 485 and 2465, ignoring the hp1740 and the 475a+dm44, sigh).

author: rstofer
author_rank: Super Contributor
timestamp: December 12, 2016, 07:37:34 pm
content: Quote from: tggzzz on December 12, 2016, 05:25:57 pmI don't use my Analog Discovery every day but it is an interesting tool with a ton of features. As long as the voltage and bandwidth limits can be met, it's a great tool! I may even buy the new version just for the larger ampacity variable voltage power supplies. And, yes, I paid full price.I didn't put the AD in my 'what if I could keep only one' scenario above. Now I have a more serious choice to make. Within its capabilities, the AD would be my first choice. Just add a Surface Pro or Surface Book computer and I have a lab in a small box. Plus all the code wienie tools, all in one place. That's pretty cool!

author: rstofer
author_rank: Super Contributor
timestamp: December 12, 2016, 09:08:17 pm
content: BTW, I just got an email from Digilent announcing a new version of Waveforms. They have add a lot of functionality like serial decoding and voltmeters as well as adding functionality to the logic analyzer. This is a HUGE upgrade!

author: PartialDischarge
author_rank: Super Contributor
timestamp: December 12, 2016, 09:47:22 pm
content: Definitively analog scopes have their place for example if- you're the lucky owner of a tek 7104 and associated modules like the 7A22 with differential inputs and 10uV vert scale.- you are doing risky measures that can toast a scope. I do resort to my expendables oldies in this case- x-y mode as mentioned gives well defined solid lines

author: tggzzz
author_rank: Super Contributor
timestamp: December 12, 2016, 10:50:07 pm
content: Quote from: rstofer on December 12, 2016, 07:37:34 pmAgain, I agree.But I use a Linux notebook or desktop, since I'm not clever enough to understand the new Windows interface, nor how to keep a Windows machine running.

author: edavid
author_rank: Super Contributor
timestamp: December 13, 2016, 12:06:22 am
content: Quote from: JanNousiainen on December 12, 2016, 11:11:28 amThe 54645 is the older version of the 54622 100MHz scope.You are probably thinking of the 54642, which is really not very common. I think you would be lucky to find one for $600 in the US. It's a lot easier to get a good deal on a TDS784.

author: David Hess
author_rank: Super Contributor
timestamp: December 13, 2016, 04:58:54 am
content: Quote from: MasterTech on December 12, 2016, 09:47:22 pmI sometimes use my 7A22 (differential 1MHz 10uV/div) or 7A13 (differential 100MHz 1mV/div) to provide high sensitivity or high common mode differential capability to one of my DSOs by connecting the vertical output of the 7000 mainframe to my DSO.QuoteI have a 545A and CA amplifier (30 MHz dual trace dual delayed sweep) which are all tubes for that. The 545A can also be used to crush zombies.

author: tautech
author_rank: Super Contributor
timestamp: December 13, 2016, 05:25:26 am
content: Quote from: MasterTech on December 12, 2016, 09:47:22 pmIf you don't trust your ability and don't have the right gear to dorisky measuresthen you shouldn't be doing them. Period.Good scope or an oldy.

author: PartialDischarge
author_rank: Super Contributor
timestamp: December 13, 2016, 06:18:48 am
content: Quote from: tautech on December 13, 2016, 05:25:26 amWell, we all can make mistakes and we tend to realize afterwards not before. Besides, the point of making a measure is exactly that, measuring something you don't know in the first place. So If I suspect something smells fishy I will go ahead, with the best of my knowledge and with the equipment I have, but I usually don't hold myself back... And If I break my hameg 305 I won't shed a tear

author: tautech
author_rank: Super Contributor
timestamp: December 13, 2016, 06:48:52 am
content: Quote from: MasterTech on December 13, 2016, 06:18:48 amQuite, but when you say "risky" I'm thinking HV and you don't get a second chance with that cause you're dead.Unknown and unseen voltages are bloody dangerous and any attempt to measure then with any equipment must be done with the utmost care using equipment and probes (if any) that are capable of protecting the user AND the equipment.From Hill Street Blues: Be careful out there.

author: PartialDischarge
author_rank: Super Contributor
timestamp: December 13, 2016, 08:14:32 am
content: oh yes personal safety is another issue that I take very seriously, more than the wellbeing of my scopes. indeed, I do handle some kVs. What I do is setup the whole thing first and then energize the system with a foot pedal via a relay after I've backed a meter or so. I also have 10kv gloves but prefer not to touch anything

author: JanNousiainen
author_rank: Contributor
timestamp: December 13, 2016, 08:34:21 am
content: Quote from: edavid on December 13, 2016, 12:06:22 amDoh! Indeed I meant 54642A/D, same series as the other two I have. I would gain 8x bandwidth and 10x sample rate and 50 ohm inputs which might be handy if I ever get active probe. For that 600+ USD does not sound too bad. The asking prices are easily double that unfortunately.Other choice could be low end first gen Inifiniums. Slow speed serial decoding option would be useful addition for me over 54642 but otherwise I think the capability would not be that different. I have gathered that reliability could be problem, there are quite few broken ones on ebay.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 14, 2016, 12:19:57 pm
content: Quote from: tautech on December 13, 2016, 06:48:52 amMy grill starter put out over 10KV. I have discharged that to myself countless times and somehow survive! I did a lot of my home made HV test probe work with my old scope. That was risky. It also gets used a fair amount when I am playing with car ignition parts. It owes me nothing and if I kill it, I have spare parts laying around.