Do you need both analogue and digital scopes for your lab? - Page 1
Forum section: electronics / beginners

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 05:33:05 pm
content: Hi do you need both analogue and digital oscilloscope for electronic hobbyist lab, I have an HP 65600a, and there are some good priced analogue scopes on eBay.Watching some YouTube tutorials videos and reading some discussion from this blog, have highlighted some characteristics that an analogue have, knowing that my digital scope is more than 20 years old, so does adding the analogue scope such as hp1740a complement my digital hp54600a scope.Thank you

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 22, 2013, 05:48:33 pm
content: If you have a good digital with intensity-graded display & fast update , that's enogh, but an analogue can be useful if you only have a cheaper digital scope.Cheap digital + used analogue will be cheaper than a good enough digital to not need the analogue.

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 06:02:07 pm
content: Thank you Mike,I am on a tight budget the Digital HP54600A 100 MHz + analogue HP1740A 100 MHz both dual channels. The cost is £180+£70= Total £250.Is there a £250 good digital scope with your suggested specs that can replace these 2 scopes?

author: c4757p
author_rank: Super Contributor
timestamp: February 22, 2013, 06:47:06 pm
content: No, there is not.

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 07:06:01 pm
content: Thank you c4757pSo with £250 budget, the combination of dual channels Digital HP54600A 100 MHz + analogue HP1740A 100 MHz is the ideal option.

author: nanofrog
author_rank: Super Contributor
timestamp: February 22, 2013, 07:13:59 pm
content: Quote from: raygb on February 22, 2013, 06:02:07 pmUnfortunately, No.Given my budget, I'm taking the less expensive DSO + analog route as well (still need a DSO, but it will wait). Still need to go through the analog and do some work to it, and they're a lot more fun to play with IMHO anyway (I really like the tactile feel of real knobs & switches vs. soft keys and encoders).

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 07:59:10 pm
content: yes nanofrog,it looks like it for me too2 scopes better than one

author: jpb
author_rank: Super Contributor
timestamp: February 22, 2013, 08:16:10 pm
content: The drawback of analogue scopes is their size. My lab has to fit onto a small workbench (desk really) so size becomes a rather important consideration when acquiring new equipment.If you have the room then there is a lot of bulky but quality kit from a few decades ago, I sometimes feel tempted when browsing e-bay but then I look at the dimensions!

author: Smokey
author_rank: Super Contributor
timestamp: February 22, 2013, 08:57:05 pm
content: There should really be an "Analog vs DSO" sticky somewhere. It might even be the topic of a quick video. There are a lot of good threads on this but it still seems to confuse people.1) Make a list of all the things you CAN'T do with a cheap modern DSO.2) Make a list of all the things you CAN'T do with an old used analog scope.3) Notice the list for #1 is really short.4) Notice the list for #2 is really long.5) Take the money you were going to spend on the old used analog scope and put it towards a better modern DSO.6) ? ? ?7) Profit!Despite a lot of people pushing the analog scope route, I haven't seen a good list of things you can't do with a modern DSO but you can with a cheap used old analog scope that doesn't include only inferred results from specialized measurements on once really high end specialized analog scopes that your average person probably wouldn't need to do.Going back to the cell phone analogy, say your daily driver phone is an ancient Nokia brick with no camera. It makes basic calls but doesn't have a camera and that's a feature you really want. Are you going to get the oldest stand alone digital camera you can find even though it is crappy by modern standards? And then carry around two basic outdated pieces of technology that together give you only the basic features you want even through you are compromising on both of them? Or are you going to get one modern phone that has both those basic features but with modern quality, plus a HUGE number of other additional features on top of that?(Once again, just talking actual performance here. Nothing beats an old analog scope sitting on the bench, functional or not, for making your lab look cool.)

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: February 22, 2013, 09:32:09 pm
content: The old HP analogue scopes look good on your bench. Especially to non electronics people.My HP1741A currently looks even better than normal, as it is in pieces. <sigh>

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 09:33:01 pm
content: Yes Smokey having a new digital scope is goodFor a starter, when the budget is tight for a beginner, any scope is good for learning; and having both is a bonus.I liked the phone analogy; old phone + old camera combination is also achievable, the picture seems to suggest.

author: nanofrog
author_rank: Super Contributor
timestamp: February 22, 2013, 09:37:53 pm
content: For me, in terms of where an analog scope is more favorable, would instances where you'd need more than 8bits of vertical resolution. Granted, there are DSO's that can do this natively, but they're rather expensive, and likely out of reach for a home lab (stand alone scope, not Picoscope or similar that requires a computer).Audio would be a good example of this IMHO, and since there isn't a need for a massive amount of bandwidth, it's far cheaper to go with an analog model.YMMV though, so the potential buyer would need to weigh their needs carefully, and determine what's the best use of their available funds.

author: EEVblog
author_rank: Unknown
timestamp: February 22, 2013, 10:30:17 pm
content: Surely you can get a useful new DSO for £250Even here in Oz you can get a useful 60MHz DSO for AU$269 (£183):http://www.triosmartcal.com.au/1764-uq2062c-digital-oscilloscope-60-mhz-500-msas.htmlSure, not the best, but more than adequate as a cash strapped starter scope.The trick with anaog scopes is not to payanythingfor it!Dave.

author: EEVblog
author_rank: Unknown
timestamp: February 22, 2013, 10:38:34 pm
content: Quote from: raygb on February 22, 2013, 06:02:07 pmYes:http://www.ebay.co.uk/itm/ATTEN-ADS1102CAL-100M-Hz-1G-Digital-Oscilloscope-7-LCD-/321063391763?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item4ac0de9213100MHz, 1GS/s, 40K for £239The HP54600A is useless as a digital scope, it's only 20MS/s.Dave.

author: Smokey
author_rank: Super Contributor
timestamp: February 22, 2013, 10:40:22 pm
content: OMG that picture is almost exactly what I had in my head when I wrote that. The phone is spot on. My mental image had duct-tape holding it together though. That's too funny!Be careful with the "resolution" of an analog scope. After all the trace is just an electron beam scanned across a phosphor screen. In addition to the scan bandwidth, that beam has a physical width associated with it. It has an inherent "resolution", and I'm not sure it's better than 8-bit digital.As far as using an analog scope for audio, it's true you can determine a lot about signal quality that way, but DSO opens up HUGE other analysis options for audio with the math functions like FFT. That will tell you way more about audio quality than just looking at a section of sine wave, even with a cheap digital FFT.

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 10:49:56 pm
content: Thank you Dave i recently purchased an HP54600A DSO around £180, in very good shape, with original folders and floppy disks, its dual channels 100MHz. The rest of the specs are in the manual, and i don’t know what they mean, will learn and find out with time.I will have to upgrade , the ATTEN scope have the modern scopes specs and it is in that price range, thank you for the advice Dave.

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 11:05:33 pm
content: Quote from: Smokey on February 22, 2013, 10:40:22 pmit shows you, Necessity is the mother of all invention

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 11:07:00 pm
content: Quote from: Smokey on February 22, 2013, 10:40:22 pmThank you, I’m learning a lot from you experienced specialists, appreciate your inputs

author: EEVblog
author_rank: Unknown
timestamp: February 22, 2013, 11:17:46 pm
content: Quote from: raygb on February 22, 2013, 10:49:56 pmThe two key figures are the sample rate in MS/s and the memory depth.The HP54600A only has 20MS/s, that makes this an ancient and fairly useless digital scope by modern standard, as it only has a single shot bandwidth of 5MHz tops, essentially not worth having on your bench apart from nostalgic value.And that is a very common beginner mistake. They think the 100MHz bandwidth is the same as a modern 100MHz bandwidth digital scope, but it's not, that only applies to repetitive sample mode, and not to single shot waveforms.Of course it's better than no digital scope at all, but you can do much better for your money.Sell it and get a cheap modern DSO, it will be infinitely more useful.Dave.

author: raymond2000
author_rank: Contributor
timestamp: February 22, 2013, 11:30:31 pm
content: Quote from: EEVblog on February 22, 2013, 11:17:46 pmYes i will sell it and upgrade, thank you Dave for the advice, certainly its more clearer for me now.i came to the right place to ask for advice , got the right answer.Thank you for the inputs

author: nanofrog
author_rank: Super Contributor
timestamp: February 22, 2013, 11:35:09 pm
content: Quote from: Smokey on February 22, 2013, 10:40:22 pmTrue.But given the cost of a 12bit DSO (best of both worlds), it's far easier on my wallet to have a used analog (have a 2445B) + decent DSO.Not as convenient as a single 12bit DSO, but is an acceptable compromise IMHO (and provide a lot of capability for the funds vs. just a DSO or analog scenario).

author: Unknown
author_rank: Unknown
timestamp: February 22, 2013, 11:40:21 pm
content: A couple of years ago I bought a Trio CS-1577A (35mhz) and a HP1661 AS (250Mhz) they were £25 and £75 from Ebay; But 2 years on, the HP is just a pain in the arse as the memory depth is so small; you know, if a Hackerspace opened where I live - I think would take them down and leave them there! ;-) I'm currently looking for a modern DSO for my next set of lab gear projects; one with I2c is a must have!

author: Smokey
author_rank: Super Contributor
timestamp: February 22, 2013, 11:41:31 pm
content: I bet a lot of beginners get this analog scope thing from that one drive time rant suggesting everyone get an analog scope. It might be time to do a follow up video and clarify when that's actually appropriate. Maybe when an older DSO compared to a modern DSO is appropriate as well. Like this, it's not always obvious and may be misleading people into spending money they could be putting towards a better piece of equipment.

author: EEVblog
author_rank: Unknown
timestamp: February 23, 2013, 01:11:07 am
content: Quote from: Smokey on February 22, 2013, 11:41:31 pmI do recommend every beginner has an analog scope for learning, if they can get it free or cheap enough. That advice remains true regardless of what DSO you have or haven't got.I do not recommend anyone buy any DSO that is not "real time", old or new. i.e. "real time" is one that has at least 4-5 times the bandwidth in sample rate. I'm pretty sure every new DSO on the market now is real time, but cheap portable ones ones like the DSO Nano are usually not.With an old 2nd hand DSO, it's almost always not worth buying, when compared against a new modern cheap DSO.Dave.

author: FenderBender
author_rank: Super Contributor
timestamp: February 23, 2013, 01:21:17 am
content: I guess it depends on the price. If you can find a good working analog scope for less than..I don't know, $50-100, I'd say go for it, but don't go spending $400 on an analog scope that was state of the art...35 years ago. They are great pieces of equipment, but it's not fun finding unobtanium parts and trying to fix the old buggers.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 23, 2013, 01:23:00 am
content: Quote from: Smokey on February 22, 2013, 10:40:22 pmIt's not about resolution - an analogue scope won't show you any more than an 8-bit digital in that respect. It's about intensity & update rate, which gives information about things like jitter, noise, how often a glitch occurs etc. by the relative brightness of different parts of the trace. Only an expensive digital scope will give you this.

author: w2aew
author_rank: Super Contributor
timestamp: February 23, 2013, 02:09:13 am
content: I'm lucky in the sense that I have access to several analog scopes ranging from 25 to 350MHz, as well as several digital scopes, to well over 1GHz. While they're all here, the scope I reach for 8 or 9 times out of 10 is one of the analogs. For me, the true live / real time feel and the intuitive nature of the natural intensity grading of the phosphor is all I need most of the time. Of course, there are times where the digital scopes are absolutely needed, and fabulous.I guess the point is - for most of my daily use, the analog scope serve me well. But, I'll always use the digital when I need the features and power it offers.It all depends on the nature of the signals you'll be working with that'll determine which scope you'll reach for more often. Of course the modern digitals will do nearly everything the analog can (plus many things it can't). I cut my teeth on the analog scopes, do I guess that's another big reason I gravitate to them.Like Dave said, if you are clever, you can often find an analog for minimal money.

author: BravoV
author_rank: Super Contributor
timestamp: February 23, 2013, 05:21:15 am
content: Quote from: mikeselectricstuff on February 23, 2013, 01:23:00 amAs an hobbyist, I used to have an old clunker > 30 yrs 20 Mhz analog scope with me, then upgraded to cheap 60 Mhz Chinese DSO that is not worth mentioning here, later had a good luck to secure a fully working and cheap analog beast Tek 2465B while ago. Agree with Mike above, at the trace's varying brightness, really minor glitches, micro spikes at etc that made a decent analog stands out against digital scope especially the cheap ones.For special cases when it comes to capture single shot or non repetitive signal, digital simply beats analog out of the water, no contest here, and when it times you need this, analog scope really just can not help you.Quote from: w2aew on February 23, 2013, 02:09:13 amDon't forget Alan, that 350 Mhz beast of yours has the unique feature that the crt tube can sweep faster than speed of light.IMO, in enthusiast/hobbyist world which usually have limited budget, a combination of "properly working" old analog + cheap DSO is the best combination you could get and yields the biggest bang for the money.The biggest challenge and major problem is getting a cheap + "still properly working" old analog scope.

author: Anquietas
author_rank: Regular Contributor
timestamp: February 23, 2013, 06:28:28 am
content: Quote from: BravoV on February 23, 2013, 05:21:15 amJust a random question, would you pay USD1000 for that scope? I can't really make a proper estimate on what's cheap and what's not. I found a 2465A, fully functioning, on eBay, starting at approx. USD700, no bids yet.

author: EEVblog
author_rank: Unknown
timestamp: February 23, 2013, 06:43:57 am
content: Quote from: w2aew on February 23, 2013, 02:09:13 amI posted a list of things a digital scope can do that an analog can't some time back on here. The list was extensive!Just the aspect of being able to single shot capture an event, or freeze the waveform is so incredibly valuable in general use, it makes any small advantage of an analog scope a pointless argument.There is simply no contest, no lab is complete (even a beginners one) without a digital scope.I use a digital almost exclusively. As the ability to single shot capture at any time and then zoom in is something you just can't live without.I've said it before, and I'll say it again, if I had to have only one scope in my lab, I'd choose a modern $300 50MHz DSO overanyanalog scope ever made.But as always, YMMV.Dave.

author: EEVblog
author_rank: Unknown
timestamp: February 23, 2013, 06:47:30 am
content: Quote from: Anquietas on February 23, 2013, 06:28:28 amThat's an insane price.This one didn't sell for US$550http://www.ebay.com.au/itm/Tektronix-2465A-Oscilloscope-350-Mhz-4-Channel-30-Day-Warranty-/360593828675?pt=BI_Oscilloscopes&hash=item53f5112b43&_uhb=1#ht_3465wt_1165or US$430http://www.ebay.com.au/itm/TEKTRONIX-2465A-350MHz-4-CHANNEL-OSCILLOSCOPE-/321058419471?pt=BI_Oscilloscopes&hash=item4ac092b30f&_uhb=1The going rate seems to be under US$300.Dave.

author: Anquietas
author_rank: Regular Contributor
timestamp: February 23, 2013, 07:00:57 am
content: Quote from: EEVblog on February 23, 2013, 06:47:30 amThanks!Good to know. I am basically limited to sellers from Europe, though, because overseas shipping costs >$400 for a package of that size/weight, or so it seems. So, I could basically buy a new cheap Chinese DSO just for the money I'd have to shell out to get the scope shipped to my location. I am considering saving my money until I can buy a new Agilent 3000X MSO 4+16, 500MHz and set up a small home lab (would take a year or two of saving) unless I find a very convincing offer on eBay. At this point I wouldn't be able to do terribly much with a scope anyway, I suppose, since I am practically the personification of inexperience.

author: EEVblog
author_rank: Unknown
timestamp: February 23, 2013, 07:06:20 am
content: Quote from: Anquietas on February 23, 2013, 07:00:57 amIn that case you'd be crazy to even consider a 500MHz MSOX3000!Sure, it's a great scope, but half that money could fully kit you out with a great beginner lab.If my lab burnt down tomorrow and I had buy new gear again, there is no way I could justify that scope.Dave.

author: Anquietas
author_rank: Regular Contributor
timestamp: February 23, 2013, 07:09:31 am
content: I wonder if scopes in Europe are ridiculously expensive,http://www.ebay.de/itm/LeCroy-9410-Dual-150-MHz-Oszilloskop-Oscilloscope-/350442115688?pt=Mess_Pr%C3%BCftechnik&hash=item5197fa5268This is a 150MHz, 2 channel analog LeCroy for roughly USD1700.Quote from: EEVblog on February 23, 2013, 07:06:20 amWhat I was thinking was that eventually I will have to upgrade the hardware, since I have no doubt about my fascination for EE. But you are right that I should start with more entry-level stuff. It's a personality defect of mine to go for stuff that sometimes ends up overwhelming me.

author: Bored@Work
author_rank: Super Contributor
timestamp: February 23, 2013, 07:37:05 am
content: Quote from: Anquietas on February 23, 2013, 06:28:28 amFor the US the prices are high. For Europe these would be typical asking prices. Not that I would pay that, but it is even a bit on the low side of what some people keep asking in western Europe. Typically these do not sell, but they offer them in the hope to find someone gullible or desperate enough to pay.And unlike the US, used instruments from reputable brands are in general expensive here. Dave just featured the 3478A multimeter. You get a used one in the US for $150. You get one here for around 300 Euro ($395) if you are in a hurry. If you are lucky you get'one for 250 Euro ($330). This is what makes the cheap Chinese crap so interesting for people, although Chinese companies like Uni-T don't even care about selling to Europe.

author: Anquietas
author_rank: Regular Contributor
timestamp: February 23, 2013, 07:47:19 am
content: Well, I think I will get a recently calibrated and refurbished Fluke PM3065, 100MHz analog 2 channel scope for EUR199. It is old, but I am sure I will still learn tons with it before I progress beyond its capabilities (in the far future).

author: M0BSW
author_rank: Frequent Contributor
timestamp: February 23, 2013, 09:10:22 am
content: My scope is only a small one Telequipment D61A 10mhz, I've always like the Tektronix scopes personally, I think you have to be careful which one you buy as ,I read there is softwre issues with one of the models , just can't remember which one, plus as does anyone know about ATTEN Dso, seem cheap enough, but are they crap, or fine for a hobbyist

author: ptricks
author_rank: Frequent Contributor
timestamp: February 23, 2013, 02:57:22 pm
content: It really depends on what you plan on doing. For me I do a lot of work with RF signals, these are not signals that would benefit from freezing the display or one shot capturing, the signals are constant and I need to see things like noise, transmission losses and eye patterns without worrying about if the digital scope is showing me something because of the way the hardware inside it is designed or if it is a setting I need to change.There must still be some demand for analog scopes because B&K precision is still making them .If you can get something like a tektronix 2246 cheap , go for it.

author: M0BSW
author_rank: Frequent Contributor
timestamp: February 23, 2013, 05:10:49 pm
content: Quote from: ptricks on February 23, 2013, 02:57:22 pm

author: mazurov
author_rank: Frequent Contributor
timestamp: February 23, 2013, 09:06:31 pm
content: I have both analog and digital scopes too. In my opinion, digital scope is good for measurements and taking screenshots. Modern ones are quite small and lightweight which is also handy. However, I still mainly use analog scopes, especially for troubleshooting - Tek475A with 1:10 probe has vertical range from 50mV/div to 100V/div which in practice means I can measure from a diode drop to line voltage with a same setup. I'm yet to see a modern DSO which would provide comparable range.

author: raymond2000
author_rank: Contributor
timestamp: May 08, 2013, 11:55:16 pm
content: my HP 1740A and HP 54600A are both sold , I am without a scopeNow looking for a 2 channels scope 100MHZ, more recent and capable than my previous digital scope around £300-£350thanks everyone for the info

author: eKretz
author_rank: Frequent Contributor
timestamp: May 09, 2013, 12:46:32 am
content: So I recently picked up a Tek TDS 754A - 500MHz and 2GSa/s, 500kpts memory. Is there anything I can't do with this scope that I would need a plain analog for? I guess this is one of the first DPO type scopes with the InstaVu.