Oscilloscope advice  - Page 1
Forum section: electronics / beginners

author: spear
author_rank: Newbie
timestamp: September 17, 2024, 09:20:22 pm
content: Hi, I’m looking to purchase my first oscilloscope but overwhelmed by the amount features they have. I don’t want to waste money on features that I would not need or use, so need advice for a good unit that will fit my requirements. I will also want a signal generator.It will only be used for audio stereo amplifier fault finding, able to display both channel sine waves simultaneously.I’ve been looking at 2 channel 70mhz scopes but this is only based on my own limited knowledge on the subject. So would really appreciate your advice.Budget is a bit limited at between £300 to £400 max.Thanks

author: Benta
author_rank: Super Contributor
timestamp: September 17, 2024, 10:52:31 pm
content: For your initial use, I'd go for an old-fashioned analog 'scope.20 Mhz is plenty, and they're super easy to use.Something like a Hameg HM203, you'll easily find a good one for 50 € on eBay.Get used to working with it, then you can make an informed choice on what you need in the future.

author: PGPG
author_rank: Frequent Contributor
timestamp: September 17, 2024, 10:54:09 pm
content: Quote from: spear on September 17, 2024, 09:20:22 pmOscilloscope that is not enough good for observing up to 20kHz signals probably not exists.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: September 18, 2024, 12:48:18 am
content: I'm with Benta.Maybe get a little adventurous and go to a Hamfest with a good flea market. Here in US old CRT scopes are going for almost nothing.You can plug the thing in and see if it works. Price should easily be well below 100 pounds. And no shipping where they seem to break every CRT they can find.There are some that are not too old that are 10-20 MHz that would meet your needs.If you do not get any probes, I find that the cheap probes from China are pretty darn good. Make sure you get the correct probes, the correct capacitance rating for the scope input.I find that for audio freq the old CRT Scopes are easier to use than the more modern Digital Scopes. I have both. Might be a good place to start.Anyway just a suggestion, and my opinion, hope not to get involved in CRT vs Digital scope discussion.

author: tatel
author_rank: Frequent Contributor
timestamp: September 18, 2024, 05:32:19 am
content: Quote from: Benta on September 17, 2024, 10:52:31 pm+1I think to find a good one for 50 € (on Ebay), you'll have to be very patient. Last week I got one for about 80 €, shipped, which seems to be good but it's still on the way, so I still don't know. Ebay prices get easily over 100 €But, being on the UK, it will probably be easier to you. Getting one at a Hamfest would be the easiest way to get it for cheap, as Wallace said.

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 06:53:14 am
content: Quote from: spear on September 17, 2024, 09:20:22 pmIt will partly depend on what interpretation you will need to place on the displayed traces.If you are intending to look at harmonic distortion, then you would need a digitising scope with a 12 bit (or higher) digitiser. A spectrum analyser might be a better choice.If you are looking at PSU noise and ripple, anything will be sufficient.If you are looking at the shape of an analogue waveform, e.g. to spot faulty components, tweak biassing or to spot when slew rate limitation causes TID, then anything will be sufficient.If you are looking at the noise levels, then you need a scope with particularly low noise. That requireslowbandwidth, as low as possible.As others have said, aworkinganalogue scope sounds like an ideal starting point. The rule of thumb is £1/MHz for something dubious (a little more for something you can see workin), and you don't need many MHz!For any scope, if you are particularly interested in valve equipment, then you will need to ensure the high voltages don't damage the scope or you, and to be sure whether or not the the chassis is connected to mains earth (the probe shield must be connected to mains earth, for your safety).

author: Mahagam
author_rank: Regular Contributor
timestamp: September 18, 2024, 07:13:17 am
content: However, modern digital scopes have one big advantage – they can automatically plot the frequency response of an amplifier.

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 07:49:24 am
content: Quote from: Mahagam on September 18, 2024, 07:13:17 amThere are limits to that. We have no idea what the OP wants and needs in that respect.

author: spear
author_rank: Newbie
timestamp: September 18, 2024, 09:11:31 am
content: Thanks for your replies. I have already read elsewhere that the analogue scopes are easier to use, however, due to limited space (in my shed) I just have enough space for a small shelf over the worktop that would accommodate a digital scope.

author: Aldo22
author_rank: Super Contributor
timestamp: September 18, 2024, 09:36:40 am
content: Quote from: spear on September 18, 2024, 09:11:31 amIf you would answer tggzzz's questions, you could get more specific help (harmonic distortion, noise levels, high voltage).

author: NE666
author_rank: Frequent Contributor
timestamp: September 18, 2024, 09:52:11 am
content: Quote from: spear on September 18, 2024, 09:11:31 amIndeed. You really don't need some 20+ year old analog door stop of unknown provenance and condition, most of which are (imho) still at silly asking prices for what they are in today's scope market.For the budget you've indicated, and given that you're in the UK, I suggest that you have a look at what Telonic.co.uk can supply. (NOTE; I'm not affiliated or connected with them in any way, nor do I gain anything from recommending them. It's just that I've used them in the past and been pleased with their pricing and customer service).Rigol DS1102Z-E 243 GBP inc. VATRigol DHO802 345 GBP inc. VATSiglent SDS802X-HD 374 GBP inc. VATAll perfectly fine for basic waveform visualisation and measurements. Yes, they are digital but you only benefit from that. They are really no harder to learn to use for the beginner, especially with some of the excellent resources available on the t'interweb. I'd liken it to learning to drive a modern 8-speed automatic car with 4wd and adaptive cruise-control etc., rather than your grandfather's first car. The latter might seem to have some simplicity appeal, until you've a few miles under your belt and realise that the latter isn't near so friendly or comfortable on long journeys or driving in stop-start traffic in town as you thought it would be.If this is your first scope and you need to embark on a learning curve, I would recommend investing your time and efforts in the contemporary rather than a history lesson.As others have said though, if you have specific requirements e.g. noise measurements, they need to be taken into account during this specifying phase.

author: PGPG
author_rank: Frequent Contributor
timestamp: September 18, 2024, 10:24:34 am
content: Quote from: spear on September 18, 2024, 09:11:31 amYou can also consider USB driven (without own screen) scopes.In my opinion in use they are generally worse than standard scopes but...We have recently bought one only because you can use it with laptop working from its battery. It allows to avoid GND loop when measuring something in AC supplied device.

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 10:25:29 am
content: Quote from: NE666 on September 18, 2024, 09:52:11 amThe OP will pay, one way or another, to gain experience.The advantages of a working old scope are thatit would be cheap enough that it could be thrown away if that turns out to be beneficial. The "sunk cost" wouldn't be an impediment.the OP would have gained knowledge so that they could get what they need, rather than what they currently think they needlow-end (new) scopes have subtle disadvantages that a beginner is unlikely to be in a position to understand. Whether the disadvantages would matter to the OP is a separate question, of coursethe OP could spend their limited budget on other equipment, potentially expanding their opportunities/capabilitiesThe one USP of a digitising scope is to capture one-off events. In audio applications, PSU startup/shutdown problems spring to mind.Old analogue scopes might be too large/heavy for the OP, but many are light and might fit in the available space.Personally I wouldn't like a scope to be on a shelf, since that would give me a crick in the neck, and I couldn't swivel my eyeballs between the trace and whatever I'm touching with the probe.

author: NE666
author_rank: Frequent Contributor
timestamp: September 18, 2024, 10:46:17 am
content: Quote from: tggzzz on September 18, 2024, 10:25:29 amThat, and recurring but infrequent events of course.A factor that I am considering is that if the OP has limited or no experience with scope use, when it comes to buying used equipment of ages past, how are they to be certain that it operates correctly in the first place? The value in paying extra for something factory fresh is that is in a known good state upon receipt. Anything 'odd' or unexpected is then clearly attributable to learning disconnect / misuse, rather than 'should it be doing this??'I also think that 50 to 100 GBP isn't such a small sighting investment, when the price of a (potentially) suitable new unit could be 'just' 250. If the OP later finds that this isn't for them, there will be some easily recoverable resale value in the latter, which is questionable in the case of the former.

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 03:59:00 pm
content: Quote from: NE666 on September 18, 2024, 10:46:17 amFair points - except £50-100 would be an unnecessarily high price. £10-20 is more reasonable.Depending on the measurements the OP wants to make, £250 is probably too low for a new scope. For example, how much are cheap 14bit scopes?One serious possibility would be the Digilent Analog Discovery, since it includes a 14bit AWG.

author: tunk
author_rank: Super Contributor
timestamp: September 18, 2024, 04:36:20 pm
content: I think this is the cheapest 2ch digital scope:https://www.eevblog.com/forum/testgear/new-$40-2ch-pocket-scope-2mhz50msps-(august-2023)/When/if the OP finds he needs more, then he can get something better.

author: tatel
author_rank: Frequent Contributor
timestamp: September 18, 2024, 04:48:42 pm
content: Quote from: tggzzz on September 18, 2024, 06:53:14 am^^^^This. Better to learn with a cheap, well-built, old analog oscilloscope, I think. I for sure know I don't want to do that kind of work (HV) with my €500 entry-level benchtop oscilloscope.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 18, 2024, 06:01:35 pm
content: Quote from: spear on September 18, 2024, 09:11:31 amTaking that comment literally:Beware of damp! Particularly with crt scopes, it's a killer...

author: Gyro
author_rank: Super Contributor
timestamp: September 18, 2024, 06:15:11 pm
content: Quote from: PGPG on September 18, 2024, 10:24:34 amIndeed, a USB scope might be an acceptable solution in this case. the Picoscope 2205A is currently £185 (UK), has 2 x 25MHz bandwidth channels (200 Ms/s total) and an MSO included. Although I don't find the UI that intuitive (although the OP might, it resembles a standard PC app more), it does include all the software features of the Picoscope S/W. This includes things like FFT display and direct distortion measurements (I don't know about frequency response plots), although measurement range is going to be rather limited by being an 8 bit scope.For around £90 the Owon VDS1022I is another option with the same bandwidth. This has galvanic isolation at the USB port so offers protection of the laptop, prevents ground loops and reduces noise without the need to unplug. It has no MSO or distortion measurements though other than FFT display. Again an 8 bit scope.The word "shed' worries me a little. Sheds can be anything from well heated and insulated dry environments to damp and cold affairs. Damp and cold storage are the worst enemies of traditional, gracefully aging, analogue scopes with all of their switch contacts and tantalum bead capacitors. [Edit: as Xena E says]On the general subject of size, a modern DSO is way shallower than a CRT analogue scope, and lighter too,but the front panel dimensions of my DS1102Z-E are almost exactly the same as my old Tek 475A analogue. Size can mean different things in different situations.

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 06:54:22 pm
content: Quote from: Xena E on September 18, 2024, 06:01:35 pmWhy "particularly with crt scopes"?N.B. Tek used to recommend cleaning their scopes' interior with detergent and water in a "wash booth". Seehttps://w140.com/tekwiki/images/6/63/Tekscope_1976_V8_N4_with_Supplement.pdfp13ff. No, I wouldn't do it either, but it does indicate why your comment may not be correct.

author: Gyro
author_rank: Super Contributor
timestamp: September 18, 2024, 07:22:38 pm
content: Quote from: tggzzz on September 18, 2024, 06:54:22 pmThe speed of the detergent wash and the 24 hours in a drying oven would seem to be an obvious difference from cold damp storage. I would expect damage to a DSO too, especially things like the encoders and maybe tactile button PCB pads.That cleaning procedure does look brutal though - Furniture polish and WD40 on the switches and pots? Ajax for the front panel!EDIT: As far as why CRT scopes, EHT and cathode bias voltage supplies come to mind.

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 08:16:55 pm
content: Quote from: Gyro on September 18, 2024, 07:22:38 pmThe past is a foreign country, they do things differently thereCompletely unconvinced that the 2450V is relevant, provided it isn't damp when switched on. My Tek485 (which I bought on a whim while collecting a 465 CRT) had been stored in something not far away from a farm shed, worked just fine apart from some unsubtle and some subtle electrolytic cap problems. The 465 CRT had been stored similarly.OTOH I have, of course, found damp damaged equipment - but without CRTs/kV.Hence I still think Xena E's comment needs justification.

author: spear
author_rank: Newbie
timestamp: September 18, 2024, 09:13:47 pm
content: Quote from: PGPG on September 18, 2024, 10:24:34 amThanks for the suggestion but have already considered the USB option and ruled it out as I would not have the space for the laptop.

author: spear
author_rank: Newbie
timestamp: September 18, 2024, 09:16:27 pm
content: Quote from: NE666 on September 18, 2024, 09:52:11 amThanks for the info, will have a look at these

author: spear
author_rank: Newbie
timestamp: September 18, 2024, 09:31:32 pm
content: Quote from: tggzzz on September 18, 2024, 06:53:14 amWell this is the problem, as a beginner with scopes, initially I'd be looking for basic fault finding but who knows, as I progress over time I may well need the more advanced features that you have outlined. With this in mind, I would be looking for a scope that has the capacity to accommodate me as required, assuming it's within my budget.

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 09:34:26 pm
content: The "it might come in" (i.e might turn out to be useful) trap is indeed beguiling.If the feature is cost-effective in all dimensions, then getting the feature is a no brainer. But if there is a cost (direct or indirect or especially lost opportunity), the decision is much more finely balanced.For basic faultfinding there is a strong argument you only need a basic scope. Any scope is better than no scopeThere are many forms of testing/faultfinding that are better addressed by different equipment. A classic example, which is outside your current requirements, is looking at digital signals.If you are interested in distortion, for example, then a dedicated distortion meter might be useful.IMHO there is a strong arguments for starting with something cheap and simple, then moving up when you know which direction represents up.

author: spear
author_rank: Newbie
timestamp: September 18, 2024, 09:38:26 pm
content: Quote from: Xena E on September 18, 2024, 06:01:35 pmThanks for the warning re damp. There are sheds and there are sheds, this one is dry and well insulated

author: spear
author_rank: Newbie
timestamp: September 18, 2024, 09:51:12 pm
content: On the general subject of size, a modern DSO is way shallower than a CRT analogue scope, and lighter too,but the front panel dimensions of my DS1102Z-E are almost exactly the same as my old Tek 475A analogue. Size can mean different things in different situations.Would you recommend the DS1102Z-E?

author: tautech
author_rank: Super Contributor
timestamp: September 18, 2024, 09:56:01 pm
content: Quote from: spear on September 18, 2024, 09:16:27 pmYour requirements are pretty basic however don't overlook features that you might grow into as experience, skill and knowledge develops.Even the $290 SDS1052DL+ will meet your needs although it's a pretty basic but reliable DSO.

author: NE666
author_rank: Frequent Contributor
timestamp: September 18, 2024, 10:27:33 pm
content: Quote from: tautech on September 18, 2024, 09:56:01 pmNot readily available in the UK and where it is, it is a very poor feature/value competitor with the other models I listed.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 18, 2024, 10:41:02 pm
content: Quote from: tggzzz on September 18, 2024, 08:16:55 pmNot only crt scopes but yes, particularly those, especially vintage ones. Older gear with its shellac and waxed craft paper insulated transformers are going to very quicky be fucked.Comment based on temperature gradients in the average outbuilding, formation of moisture on internal surfaces, degradation of insulation and failure of mains transformers. Moisture absorbtion by components and circuit boards.Personal experience based on acquisition of four scopes free, due to the owner having stored them from working purchases, in a typical "shed" for a number of years.All were dried thoroughly before attempting use.Three were badly damaged internally by damp ingress.A Cossor 1035 that had a shorted EHT winding on the mains transformer, and on investigation and removal of the winding before repair, was found to have internal green corrosion.Tektronix 310s, with a buggered transformer.An Kikusui 7100 (?) BER With switching and controls damaged as well as tracking circuit board material.Yes I understand that it's possibly recommended to wash and bake equipment, I've cleaned vintage stuff with a pressure washer and TFR, then baking it dry... but to operate it wet or allow it to stay wet, is no comparison.I sense that comments made are done so by persons possibly accommodating their equipment in a 'shed', if it's dry, and kept at a stable temperature that prevents the formation of condensation, that's OK.Drying equipment out when already damaged won't do FA to help.I know there will always be the contributors that will give examples of sensitive electronic equipment working fine after being fished out of the local duck pond, or years in a mouldy old shed, but that's just jammy good luck or a load of old bollocks.Quote from: spear on September 18, 2024, 09:38:26 pmthen you're OK!

author: tggzzz
author_rank: Super Contributor
timestamp: September 18, 2024, 11:20:41 pm
content: Quote from: Xena E on September 18, 2024, 10:41:02 pmSo, as I expected, the specific reference to CRT scopes isn't valid.Old equipment badly stored, well of course that can be a problem. So can putrid components such as modern alkaline batteries.Not all CRT equipment is like that, of course. I have had several 50yo Tek1502s that can be stored under 12inches of water. The main problem is the putrid batteries.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 19, 2024, 12:08:22 am
content: Quote from: tggzzz on September 18, 2024, 11:20:41 pmI said Particularly not specifically.Mostly based on mains derived EHT overwinds... very susceptible. But ... news flash ... moisture and bench test equipment are not best friends.Quote from: tggzzz on September 18, 2024, 11:20:41 pmStrawman argument par excellence! Well done. 👏😃A Tek 1502 is a reflectometer it's not a bench oscilloscope. and it was designed to be sealed against moisture ingress...My comment was meant to help the OP, if you want to keep your kit at the bottom of the Atlantic, please feel free to do so.😁👍🤣Regards,Xena.

author: tautech
author_rank: Super Contributor
timestamp: September 19, 2024, 12:28:15 am
content: Quote from: NE666 on September 18, 2024, 10:27:33 pm100%UK is supplied from Germany HQ to which the UK sellers are regularly placing orders so models not in local stock can be sourced promptly.That's why we don't stock SDS1052DL+ and instead settle for SDS802X HD as our base model 2ch DSO which are totally in a different league to even the others you listed.

author: tggzzz
author_rank: Super Contributor
timestamp: September 19, 2024, 12:34:13 am
content: Quote from: Xena E on September 19, 2024, 12:08:22 amIn English "particularly" means "specifically" and/or "especially". Or are you using another less usual meaning of "particularly? If so, enlighten us.FFI see any dictionary, e.g.https://www.dictionary.com/browse/particularlyhttps://www.wordnik.com/words/particularlyQuoteYour comment may have been meant to help the OP, but it was - as you have "clarified" - wrong.As per your original statement "Particularly with crt scopes, it's a killer...", the Tek1502 is a CRT scope, combined with a signal generator.It is a small instrument that fits easily on a bench.>80% of the 1502s I've had have not been sealed against moisture ingress. One of them might have been, but I never put it to the test.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 19, 2024, 02:18:52 am
content: Quote from: tggzzz on September 19, 2024, 12:34:13 amOK. I sense this seems important to you, so have it your way, though I'm not sure quite what point you want to make?My meaning was "****** but not meaning exclusively". My apologies, English is a third language, (insert your own word).Perhaps the 'moisture' affected equipment that I've seen was caused by some other phenomenon being as you have so kindly pointed out that I am wrong.Regards,Xena.

author: tggzzz
author_rank: Super Contributor
timestamp: September 19, 2024, 08:14:31 am
content: Quote from: Xena E on September 19, 2024, 02:18:52 amIf you are going to correct someone else's language, it is wise to be sure that your correction is correct. Given "Xena" can be used to imply "foreign/stranger", I did wonder if English wasn't your native language. ("Wonder" because your English is pretty good.)I strongly suspect that damp/moisturedidaffect the other equipment; there are many obvious and subtle mechanisms by which that can happen. It can also happen even when stored in non-damp domestic rooms, e.g. the infamous RIFA capacitors which should be replaced on sight. But you claimed that "CRT scopes" are especially susceptible to damage by those mechanisms; they aren't.Everyone makes mistakes, and the best course of action is to admit the mistake or clarify the intended meaning, as appropriate. You chose to do the opposite.

author: tautech
author_rank: Super Contributor
timestamp: September 19, 2024, 08:31:31 am
content: Quote from: tggzzz on September 19, 2024, 08:14:31 amYet the original Xena we all know and love is K1W1 and her English is as good as yours or mine.

author: tatel
author_rank: Frequent Contributor
timestamp: September 19, 2024, 08:41:20 am
content: If you want a DSO that will allow you to grow into it, then I would go for some of the new 12-bit models, probably with 4 channels, even if you only need 2 channels at this time. Probably a Siglent better than a Rigol. That would be the most future-proof option IMHO.

author: tggzzz
author_rank: Super Contributor
timestamp: September 19, 2024, 09:18:51 am
content: Quote from: tautech on September 19, 2024, 08:31:31 amIn that case, in what does she mean by "English is a third language"? I presume English iswidelyspoken in New Zealand!

author: tggzzz
author_rank: Super Contributor
timestamp: September 19, 2024, 09:33:54 am
content: Quote from: tatel on September 19, 2024, 08:41:20 amFor audio 12-bit would be better than 8-bit, especially when looking at the frequency domain. 14-bit would be even better, of course.For audio, the noise level might be an important consideration. The scope determines the quantisation and thermal noise, but not EMI. (My house is riddled with 96.4MHz)For valve audio equipment, withstanding high voltages might be important. (Alternative: use cheap disposable equipment)With high voltages, attaching a probe, moving hands away, and only then turning on equipment is an important safety technique. That can be difficult where components don't have leads, e.g. much ordinary low voltage equipment.Whenever safe, being able to quickly and easily move a probe between nodes is very desirable. If the trace is not visible next to the probe, there is an increased the chance the probe will move/slip. For that reason, I strongly prefer the scope to be on the bench.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 19, 2024, 05:20:36 pm
content: Quote from: tggzzz on September 19, 2024, 08:14:31 amIf I make a mistake, I apologise, I will apologise to you as you seem to consider I have offended you for which I am truly sorry.My original post was, if it's not clear, warning of the possible dangers of damp storage, I said Particularly CRT scopes because of the greater risks to the EHT for the final anode, (or cathode as is often the case), causing permanent damage to the insulation. If this is incorrect then again I'm sorry, but unless proven otherwise I will continue to hold that belief.Yes low voltage gear will also suffer, but an eht overwind flash over is often immediately fatal to the equipment, and in my opinion a more likely scenario in stressed insulation, causing permanent damage.As to semantics, to my educationparticularlymeans foremost or most importantly, notexclusivelywhen used to sufix a statement. Perhaps I should have annunciated the general risk to electrical equipment as an anterior comment, for it to make sense.I read your posts to suggest that it didn’t matter that an oscilloscope became damp! I was greatly amused that you claimed your Tektronix 1502 TDR would work in 12 feet depth of water: Thank you for the correction by the way, I have always understood 'TDR' to stand for 'TimeDomainReflectometer, I wasn't aware they were considered as being general purpose oscilloscopes... that doesn't mater, it is not of any interest to me, but thank you, now I know.If you think I make a mistake, again, as it seems to be importantto youand make you upset, I am sorry, but I still don't grasp your point, and I can't appreciate it's importance to you.Regards,Xena.

author: tggzzz
author_rank: Super Contributor
timestamp: September 19, 2024, 06:17:26 pm
content: Quote from: Xena E on September 19, 2024, 05:20:36 pmA TDR cannot be used as a general purpose scope - and nobody has suggested they can. OTOH a general purpose scope can be used as a TDR: just add a signal generator as found in a TDR.That TDR uses exactly the same circuits and technology as other CRT-based scopes, and so it has the same.failure mechanisms. Since it can bestoredin 12inchesof water (and operated in the driving rain), clearly damp is not a complete killer.We agree damp storage can be a problem, for all equipment. RIFA delayed action smoke generators are always a problem even in non-damp storage; the humidity slowly penetrates the epoxy coating.Anyway, we seem to have come to an agreement/understanding about this sub-topic.

author: Gyro
author_rank: Super Contributor
timestamp: September 19, 2024, 08:50:08 pm
content: Quote from: spear on September 18, 2024, 09:51:12 pm(Quote fixed)Getting back on topic...Would I recommend the DS1102Z-E? For me - yes, for you - I don't know. I'd been thinking of a desktop DSO for a while and bought it because it was on offer on Amazon for £235, probably the second most amount I've spent on an item of TE. For me, the reason was a nice deep buffer for capturing and looking at infrequent events. Siglents are reputed to be easier to drive, but it's intuitive enough for me, I've got used to loads of different scopes over the decades so the cost difference wasn't worth itfor me. It's good and solidly constructed and does everything I want. If you want to look at Dave's review and teardown videos, it's simply the DS1054Z but with two channels and an ext trigger rather than four and has all the options factory enabled. One thing I have found to be a surprising source of irritation is the need to transfer screen captures to the PC via memory stick rather than just clicking the save button on a USB scope, I wasn't expecting that to bug me so much. I'm not going to go to the hassle of networking or USB hosting though, I'm running Linux anyway and the Rigol app doesn't support that.I don't subscribe to Dave's 'beginner entry level scope' mindset or the 'why do they still make 2 channel scopes' (because you can buy them cheaper!). I buy tools to do the jobs that I want to do. I've had a decent high bandwidth Tek analogue scope for nearly 40 years, which is still good for RF stuff.I bought a 16 bit Picoscope ADC216 20 years ago, literally just before they discontinued them and shamed/conned Pico into giving me one of their last remaining USB parallel adaptors. I added a USB isolator and linear regulated PSU to get rid of the very small residual 50Hz harmonics and with it's low 333kS/s sample rate it is as quiet as the grave for low distortion, low noise audio. That was probably my most expensive TE purchase ever. I need to run it in an XP 32bit virtual machine but that's fine.Other than that, in 2015 I bought one of the first VDS1022I isolated USB scopes and I think I did the first ever teardown, which sort of became the master thread (https://www.eevblog.com/forum/testgear/owon-vds1022i-quick-teardown-(versus-the-hantek-6022be)/). It's a handy little, easy to drive, 25MHz 100MS/s scope that is still available and does most things well, especially with the alternative S/W that's available. The only shortcoming is the small 4k buffer and no protocol decoders but that's not an issue unless you want to capture infrequent events.The number of bits you need depends on what you are doing with these audio amps. If you were planning design and upgrades then number of bits would be more important for distortion analysis. If you just want to see how far the signal is getting and whether it's basically the right shape then 8 bit is probably fine and the simpler to drive, the better. Even for audio bandwidth, it is good to have a scope that goes to a few MHz to look for oscillations. As for a signal generator, I don't have an AWG or MSO or whatever, just a nice second hand analogue very low distortion Topward signal generator and a Function generator to go with my 16 bit Pico. I don't need some fancy box with a big LCD display, encoders and keypads that looks like a scope itself to produce a 1kHz or 10kHz sinewave (likewise power supplies). Keep an eye on ebay and make sure you can get a service manual.Only you know what you are going to do in future. If you're going to get into micros, higher speed logic etc. then facto those in now. If your ambitions don't go any further than repairing basic audio gear, then my attitude is buy the tools to do that job and divide your budget accordingly.

author: rstofer
author_rank: Super Contributor
timestamp: September 20, 2024, 05:53:55 pm
content: To my limited knowledge, there are two features of a DSO that are not available on an analog scope: Single shot trigger which is useful when triggering just once on a specific event, freezing the image and preventing overwriting the image should a second trigger occur. Second, the Auto button which will analyze the signal and set the t/div and V/div automatically. Will it always be the exact setting you need? Probably not... But it will get the scope out of some squirrelly setup used previously and get a trace on the screen.These two features make the DSO much more useful than an obsolete analog scope. However, you can buy a lot more bandwidth for little money with a used analog scope. Hence, I have an old Tek 485 for 350 MHz bandwidth and a Rigol DS1054Z for daily use and features.https://www.amazon.com/Rigol-DS1054Z-Digital-Oscilloscopes-Bandwidth/dp/B012938E76These days I would probably buy one of the Siglent scopes but the Rigol serves me pretty well.OTOH, were I just starting out in electronics, I would take a long look at the Digilent Analog Discovery 3. Two channel scope, two channel arbitrary waveform generator, dual power supply (limited low voltage) and a bunch of digital IO for protocol analysis or simple IO. Of course, all of the functionality can be controlled via a script if desired. This is a very useful gadget for the student.https://digilent.com/shop/test-and-measurement-devices/essential-instruments/analog-discovery-3/

author: BillyO
author_rank: Super Contributor
timestamp: September 21, 2024, 11:15:05 pm
content: Quote from: rstofer on September 20, 2024, 05:53:55 pmBeg to differ on this, not that it matters other than "the facts". Even my Tek 465 has single shot trigger. Usually used with a camera to get clean trace records. So, there are quite a few high end CRO scopes that have this feature. Jus' say'n.

author: Gyro
author_rank: Super Contributor
timestamp: September 22, 2024, 09:22:50 am
content: Quote from: BillyO on September 21, 2024, 11:15:05 pmIndeed. I remember taking my 475A into our new lab (whilst waiting for the bulk of our equipment and DSOs*to arrive from head office) to check out some 10s of ns logic signal relationships using single shot. It required the lights off, dark adapted eyes and the screen shroud but it was achievable. Getting the scale illumination just right was critical to extracting actual timings using persistence of vision. It's the reason that those old Tek scopes have what seems like a ridiculously high brightness adjustment range. Obviously a skill reserved for the past, but it was surprising what you could do with them at a pinch.*This was in the days when the TDS540 was cutting edge.

author: tautech
author_rank: Super Contributor
timestamp: September 22, 2024, 09:26:10 am
content: Quote from: BillyO on September 21, 2024, 11:15:05 pmAnd the trigger suite to make the best use of it with ?

author: Gyro
author_rank: Super Contributor
timestamp: September 22, 2024, 09:32:42 am
content: Quote from: tautech on September 22, 2024, 09:26:10 amThat seems like a rather fatuous comment.Tek analogues were renowned for their triggering sensitivity compared to HP back in the day. Of course it was edge only but you had Polarity, AC, DC, HF reject, LF reject etc.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 22, 2024, 09:42:04 am
content: Quote from: Gyro on September 22, 2024, 09:22:50 amA W. Heath Robinson technique that can be used, if it's required to snapshot a trigger event on a CRO is video it with anhandymobile phone, then pause and screenshot an individual frame.Works in some instances anywayQuote from: Gyro on September 22, 2024, 09:32:42 amHas anyone yet ever managed to trigger a vintage HP scope, (joke BTW before the fan boys jump all over the comment), but theywerefamous for the wrong reasons.X

author: pdenisowski
author_rank: Super Contributor
timestamp: September 22, 2024, 01:37:11 pm
content: Quote from: rstofer on September 20, 2024, 05:53:55 pmI can think of alotmore than twoQuote from: rstofer on September 20, 2024, 05:53:55 pmSome setups are so squirrelly you need to do a preset before you do an autoset. One of the first things I learned as a field applications engineer was to start every demonstration by showing how the preset button works ….

author: BillyO
author_rank: Super Contributor
timestamp: September 22, 2024, 06:47:37 pm
content: Quote from: tautech on September 22, 2024, 09:26:10 amOf course not. I was just offering a fact check.