Choosing an oscilloscope - Page 1
Forum section: electronics / testgear

author: PurpleAmaranth
author_rank: Contributor
timestamp: October 02, 2020, 11:13:39 pm
content: Hello,I'm new to the forum (and to electronics in general), and I hope I'm allowed to make a post like this given that there is already lots of info about oscilloscopes on here. Anyway, I'm debating between three scopes of around the same price: Tektronix 2235 AN/USM 488, Fluke PM3370A, and an old Soviet C1-99. I've read lots of good about Tektronix in general, and not much about Fluke, but the Fluke is analog and digital (and has something called Z-Axis input), so I am wondering if that is a good thing. As for the Soviet one, it's just got so many buttons, maybe it has greater functionality, I've read good stuff about it too? (it looks really cool lol)Which one would you pick? Or none of them, and wait for something better to come up? Idk much about this stuff, but I am going into electrical engineering, so I figure I'll learn a lot more as the years go by!Thanks!

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: October 02, 2020, 11:32:27 pm
content: Don't buy an old scope, at least not one that old. For your target budget, you really can't go far wrong with a Rigol DS1054Z which can be 'upgraded' to a DS1104Z with all options unlocked simply by googling "riglol". Rigol usually give you everything but the bandwidth upgrade.

author: PurpleAmaranth
author_rank: Contributor
timestamp: October 02, 2020, 11:50:40 pm
content: Thanks for the advice. But the Rigol seems to cost about double what I can afford to spend. Are the older ones really that bad? Should I just wait until I can afford one?

author: george.b
author_rank: Frequent Contributor
timestamp: October 03, 2020, 12:03:24 am
content: If you can get them for cheap, well, then I say go for it. I think I'd go for the Tek 2235, because, well, it's a Tek, service information about it is plentiful, etc.A Soviet scope sounds interesting for the novelty factor, but if Soviet scopes are anything like their calculators, then I wouldn't expect it to be reliable.The PM3370A has only 100MSa/s on the digital side, which makes it not terribly useful in that function beyond some 20MHz, but the ability to take single-shot captures is very nice to have nonetheless. Whether that's enough to tip the scales against the Tek depends on what you'll mostly be using it for.The problem with buying old scopes is that sooner or later there'll be something to repair. Been there, done that, got the t-shirt. Especially with the Philips (Fluke, whatever), you're looking at a re-capsoon. I have a PM3055 myself and the Philips axial capacitors in there are crap. Oftentimes, to repair an oscilloscope, you need another one, and if that's going to be your only scope, you might find yourself without an usable scope one of these days (it may be tomorrow, or it may not happen for years - who knows, they're old).If the price isn't too far from the DS1054Z, I'd suggest you go for it instead, as it'll run circles around any of those 3 in features and reliability. The usage cases where analog scopes are better are, IMHO, very marginal.

author: nctnico
author_rank: Super Contributor
timestamp: October 03, 2020, 12:06:19 am
content: To the OP:This question has come up a million times already so it is better to search for 'oscilloscope' in this section. If money is an issue then this is something to consider:https://www.eevblog.com/forum/testgear/fnirsi-1013d-100mhz-tablet-oscilloscope/At least it has storage and some decent memory depth.BTW I disagree about the RIgol DS1054Z. It is very outdated; people keep recommending it out of momentum but there are better options out there nowadays. Just search this section a little.

author: 0culus
author_rank: Super Contributor
timestamp: October 03, 2020, 12:10:39 am
content: Quote from: PurpleAmaranth on October 02, 2020, 11:50:40 pmThey aren't (I have a lab full of old oscilloscopes that are still in service), but you do have to understand that repairs may be needed with old equipment. If you're a novice, this may well not be the best project for you to take on unless you have someone mentoring you (in person, over your shoulder ideally).CROs have some hazardous voltages inside them, so you definitely want to understand what you are doing before you poke around in one. However, you can learn. Lots of folks here and at TekScopes who are willing to help if you are willing to learn.The 2235 aka AN/USM 488 should be a solid general purpose scope. I don't know of any specific pitfalls with it, but I'm sure there's folks here and at TekScopes who know. If it's cheap, why not? Worst case is it becomes a repair project for later.Ultimately it comes down to what you need in a scope. The vast majority of scope use cases are served perfectly fine by a CRO. The others are where modern scopes really shine. Of the three you mention, I would definitely take the 2235 over the others. The online community around Tek CROs is large, much larger than the fluke one I bet and I'm sure the Soviet one is going to be a tough project indeed if it needs any work.As nctnico suggests, you should do some searching as this topic has been absolutely done to death on this forum.

author: Fungus
author_rank: Super Contributor
timestamp: October 03, 2020, 02:14:10 am
content: Quote from: nctnico on October 03, 2020, 12:06:19 amIt depends a lot on where you live and what's available. If youre in the USA the net one of these instead, no question:https://www.tequipment.net/Instek/GDS-1054B/Digital-Oscilloscopes/?search=trueIt's under $300 with the EEVBLOG discount and it's a better 'scope than the Rigol.Anywhere else? it's not so clear. The next step up is quite a lot more money.People don't only recomend the Rigol out of momentum, they recommend it because it works. It's plenty of oscilloscope for most people.

author: Fungus
author_rank: Super Contributor
timestamp: October 03, 2020, 02:17:00 am
content: Quote from: george.b on October 03, 2020, 12:03:24 amThey'd have to beVERYcheap. Otherwise you'll have something huge and hot that adds $10 or more to your electricity bill each month ... and will likely need fixing.They're also nowhere near as capable as even a cheap DSO. Would you really go back to a 'scope with no storage?

author: 0culus
author_rank: Super Contributor
timestamp: October 03, 2020, 02:26:20 am
content: Quote from: Fungus on October 03, 2020, 02:17:00 am$10 to your electric bill? Where do you live where your electricity prices are that high??? My wholelabmight add that a month to mine over not having it, and I've got stuff that uses way more wattage than 2235 will.

author: bdunham7
author_rank: Super Contributor
timestamp: October 03, 2020, 02:35:40 am
content: The Tek 2235 should also have Z-axis (blanking) input as well, but unless you are doing vector graphics or something unusual, its not something you really need.What country are you in? People in the US don't always consider how difficult or expensive it can be to buy stuff in some places. That said, if you are just starting out and aren't especially interested in vintage electronics, you'd probably be better off saving up until you can buy at least the lowest-cost model DSO from known company that has sales, and if possible, support, where you live.How much are the used scopes you are looking at? Can you try them first or do they have any warranty from the seller? Here (US) you can get a bottom-of-the-line 50MHz DSO from Siglent, with a warranty, probes and support, for $259. Depending on what is available to you, another brand might be a better option.

author: james_s
author_rank: Super Contributor
timestamp: October 03, 2020, 02:41:46 am
content: Quote from: 0culus on October 03, 2020, 02:26:20 amYeah a 2235 will draw what, 60 watts? I don't know about others here but I probably run my scope for an hour on average on the days that I use it. How often I use it depends very heavily on what projects I'm working on but unless you're running the thing on alkaline D cells I don't see it costing $10 a month. We're not talking huge 1960s Tek boatanchor.

author: Fungus
author_rank: Super Contributor
timestamp: October 03, 2020, 02:42:35 am
content: Quote from: bdunham7 on October 03, 2020, 02:35:40 amZ-axis is used to control the brightness of the beam, it's essential for making pretty oscilloscope pictures.(and that's literally the only reason you should be getting a green-screen 'scope these days...)

author: Fungus
author_rank: Super Contributor
timestamp: October 03, 2020, 02:45:48 am
content: Quote from: james_s on October 03, 2020, 02:41:46 amThis needs settling. Does anybody have one and a meter to measure the power use?nb. Depending on where you live it can either save money on heating bills in the winter or cost you extra money on AC bills in the summer.

author: Fungus
author_rank: Super Contributor
timestamp: October 03, 2020, 02:46:58 am
content: Quote from: bdunham7 on October 03, 2020, 02:35:40 amOTOH you might want more than 2 channels...

author: george.b
author_rank: Frequent Contributor
timestamp: October 03, 2020, 02:57:34 am
content: Quote from: Fungus on October 03, 2020, 02:17:00 amYeah, I meant cheap as in less than $100, which would be significantly cheaper than a DSO. Obviously, I agree, a DSO is much better, but sometimes an old analog one is all you can get, so I wouldn't brush it off. Took me a while to get my first DSO - they don't come cheap in my corner of the world.

author: tautech
author_rank: Super Contributor
timestamp: October 03, 2020, 03:04:03 am
content: Quote from: Fungus on October 03, 2020, 02:46:58 amOTOH many don't.

author: bdunham7
author_rank: Super Contributor
timestamp: October 03, 2020, 04:11:43 am
content: Quote from: Fungus on October 03, 2020, 02:45:48 amYes, or I did. I've overhauled a 2235 and a 2213A recently and I use the iso-variac, so I see the current. Both of them use less than 0.5A, IIRC, and they don't have a fan--they barely get warm except for the power supply transistors which run just below their melting point. I only have a 2221A at the moment and it uses 0.8A, but it has a fan and a whole DSO/logic board to run.

author: tautech
author_rank: Super Contributor
timestamp: October 03, 2020, 04:19:00 am
content: Quote from: bdunham7 on October 03, 2020, 04:11:43 amYou really need qualify this with your mains voltage as 0.8A*235VAC = 188WAny modern DSO will at most use just 1/3rd of that.Yeah I know, you're on 115VAC but you'll now get the point.

author: 0culus
author_rank: Super Contributor
timestamp: October 03, 2020, 04:20:32 am
content: My 1960s boat anchor 585A uses over 700 watts. Fight me.

author: bdunham7
author_rank: Super Contributor
timestamp: October 03, 2020, 04:23:19 am
content: Quote from: tautech on October 03, 2020, 04:19:00 amI'm just reporting the data. You can do the math!Oh, and the voltage would be exactly 120VAC (adjusted) and I don't know the PF, so....Anyway, a 2235 runs as cool as a cucumber. And as quiet as one, too.

author: tautech
author_rank: Super Contributor
timestamp: October 03, 2020, 04:24:04 am
content: Quote from: 0culus on October 03, 2020, 04:20:32 amAKA space heaters.

author: bdunham7
author_rank: Super Contributor
timestamp: October 03, 2020, 04:25:22 am
content: Quote from: 0culus on October 03, 2020, 04:20:32 amIsn't that the model with like 80 tubes?

author: BravoV
author_rank: Super Contributor
timestamp: October 03, 2020, 04:35:06 am
content: Quote from: PurpleAmaranth on October 02, 2020, 11:13:39 pmOld scope has a risk, if its broken, most of the times, in order to fix an old analog scope, you will need "another" working 2nd scope, assuming you're skilled & knowledgeable to fix it, which in this case you are not.From above choices, none, buy a new scope, or much less expensive one, but new and presumably with 1 year warranty.A working cheap scope, is much better than a super duper scope but its broken or somehow not working right.

author: 0culus
author_rank: Super Contributor
timestamp: October 03, 2020, 04:43:59 am
content: Quote from: tautech on October 03, 2020, 04:24:04 amDude, it's gonna be awesome here in a couple months.Quote from: bdunham7 on October 03, 2020, 04:25:22 amMore like 50-60, but it's purely academic. It cranks out heat. The dual beam models like the 555 and 556 had more toobs, necessarily, since they were essentially two scopes in one case sharing a dual gun CRT and a power supply.

author: tautech
author_rank: Super Contributor
timestamp: October 03, 2020, 06:05:20 am
content: Quote from: 0culus on October 03, 2020, 04:43:59 amAwesome, yeah right. A scope you can only use in the winter months.

author: 0culus
author_rank: Super Contributor
timestamp: October 03, 2020, 06:15:42 am
content: Quote from: tautech on October 03, 2020, 06:05:20 amI have A/C...and apparently way cheaper electricity than some folks.

author: David Hess
author_rank: Super Contributor
timestamp: October 03, 2020, 12:35:13 pm
content: Quote from: PurpleAmaranth on October 02, 2020, 11:13:39 pmOf those, the Tektronix 2235 is the best documented and easiest to repair. The Fluke PM3370A is a lot more complicated because of its digital storage capability and I would not recommend it unless you are prepared to repair and maintain a more complex instrument. I would say the same thing about the Tektronix 2230 or 2232 which are 2235s with added digital storage capability, the extra complexity makes them more difficult to maintain.I always wanted one of those Flukes but ended up with Tektronix 2230s and 2232s instead.Quote from: george.b on October 03, 2020, 12:03:24 amThe 50 MHz Fluke has a 100 MS/s real time sample rate, which is the same as its contemporaries like the Tektronix 2232 and completely sufficient since it also supports peak detection and equivalent time sampling for a much higher sample rate on repetitive signals.QuoteThe storage capability is very useful but adds considerable complexity to an old oscilloscope.

author: Fungus
author_rank: Super Contributor
timestamp: October 03, 2020, 02:13:00 pm
content: Quote from: David Hess on October 03, 2020, 12:35:13 pmSomebody who's buying their first oscilloscope and trying to save money shouldn't be thinking of repairing or maintaining at all, IMHO.An entry level DSO isn'tthatexpensive.

author: 0culus
author_rank: Super Contributor
timestamp: October 03, 2020, 07:20:10 pm
content: If he can get it cheap it could be something to grow into even if it turns out to be a project.

author: tautech
author_rank: Super Contributor
timestamp: October 03, 2020, 08:01:15 pm
content: Quote from: 0culus on October 03, 2020, 07:20:10 pmBut lessens the budget to get something better and just stifles getting on with your projects.For once I'm with Fungus and his thanker Nico on this one.If one gets a hankering to fix scopes later there's plenty of cheap ones available if you are patient and by then you've become a little proficient using a scope.

author: 2N3055
author_rank: Super Contributor
timestamp: October 03, 2020, 09:01:17 pm
content: Quote from: tautech on October 03, 2020, 08:01:15 pmI agree too. To repair old scope, most of the time you need another scope...That makes it a nightmare for beginner with very little money.Old scope cannot be first and only scope, unless you get working one for free or close to free.You can get new scope with warranty for less than 300€ (+tax). I sold my barely used DS1074Z for 200€ with 4 new testec 150 MHz probes and really super high quality, brand new Rigol bag. There is alsohttps://shop.rigol.eu/demo equipment shop. They give warranty (slightly shorter but nevertheless a warranty) and prices are good..

author: David Hess
author_rank: Super Contributor
timestamp: October 03, 2020, 09:55:20 pm
content: Quote from: Fungus on October 03, 2020, 02:13:00 pmYou have to cut the coat to fit the cloth. If he says that he cannot afford a reasonable new DSO, but can afford a working 2235, then some oscilloscope is better than no oscilloscope. Sometimes one has to make the best of a bad situation, or even take a risk.PurpleAmaranth does not give a location or price, but I would not spend more than $100 for any 2235, and I would not buy any new DSO which cost less than $500.

author: tggzzz
author_rank: Super Contributor
timestamp: October 03, 2020, 10:06:33 pm
content: Quote from: David Hess on October 03, 2020, 09:55:20 pmPrecisely.Any working scope is better than none, unless the money could be better spent on other equipment.With skill and imagination you can do a hell of a lot without a scope!

author: David Hess
author_rank: Super Contributor
timestamp: October 03, 2020, 10:12:14 pm
content: Quote from: tggzzz on October 03, 2020, 10:06:33 pmAnd for what it is worth, a Tektronix 2235 is a fine oscilloscope. My go-to oscilloscope is a 2232 which in analog mode is a 2235 with display readout capability.If it is in running condition, then a Fluke PM3370A should be even better despite having half the bandwidth; 50 MHz is plenty for most applications. But I would be concerned that a PM3370A is more difficult to maintain and repair if necessary.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: October 06, 2020, 12:31:57 am
content: I realize I'm 'lucky' to be living in the US but I only paid $285 for my DS1054Z as an open box item that I also got an eevblog discount on.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: October 06, 2020, 12:56:41 am
content: Ask the guys on Groups.io TekScopes group about the Tek. They can give you their opinion and a good price recommendation.https://groups.io/g/TekScopesIf something bad happens to a scope, there are plenty of people who can help. The other scopes are uncertain as to even documentation.

author: BravoV
author_rank: Super Contributor
timestamp: October 06, 2020, 03:48:14 am
content: Quote from: Wallace Gasiewicz on October 06, 2020, 12:56:41 amLike easily to source or get donated or cheaply unobtainium chip ?

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: October 06, 2020, 05:11:11 pm
content: Yes , I even had a guy send me a nixie driver chip for an old HP counter free. This was from the HP Equipment group on Groups ioAfter I installed it and it worked, I reported back to him and volunteered to pay, he considered my reply as payment since he said it reinforced his chip removal technique.Another time I had a problem with "bounce" (each push of the key would make multiple entries; 111 instead of 1) on an old Marconi SA, someone told me exactly what the problem was and which component to replace, another 25 cent fix. Marconi group.For the most part, these groups are quite helpful and extremely knowledgeableWally

author: David Hess
author_rank: Super Contributor
timestamp: October 06, 2020, 08:30:16 pm
content: Quote from: Gandalf_Sr on October 06, 2020, 12:31:57 amOne of my 2232s and 2230s were $80 each, but I live in the US.

author: rstofer
author_rank: Super Contributor
timestamp: October 06, 2020, 10:15:27 pm
content: I have had several analog scopes over the last 60 years and NONE of them compare to the DS1054Z. The modern DSO is in an entirely different class in terms of capability. Single shot mode alone is worth waiting to buy the DSO. The number of measurements a modern DSO can do is staggering. They're on a completely different planet.I have a Tek 485 350 MHz 2 channel scope I bought about 15 years ago and, in terms of bandwidth, it is great. It was a fantastic scope when it was built but that was a long time ago. It was introduced in March of 1972.In my view, every dime you put into a worn out analog scope is wasted. You will eventually want the DSO for the capabilities anyway and it's only a matter of time before the analog scope just rolls over and dies.Today, I would be looking at the Siglent SDS 1204X-E (200 MHz 4 channel and relatively expensive) or unlocking the SDS 1104X-E to get the same 200 MHz bandwidth. Four channels is arguable so the SDS 1202X-E or SDS 1102X-E are the lower priced 2 channel scopes. I think the SDS 1102X-E can be unlocked for 200 MHz.I wanted 4 channels specifically for decoding SPI. Lacking that requirement, two channels would be fine and that's all there have been for many years. Four channel scopes were extremely rare and very expensive.Entry level: Rigol DS1054Z (unlocked to 100 MHz) or Siglent SDS 1104X-E (unlocked to 200 MHz). $349 and $499 respectively at Amazon. The Siglent is $150 more but can reach 200 MHz. The Siglent is reported to have a better user interface.You're right, there are a bazillion threads just like this with the same people giving the same replies, over and over. Nothing changes very fast in test equipment.And, yes, the DS1054Z is 'mature' but that also means they finally ironed out the bugs and that took a couple of years. I truly don't know where that stands with the Siglent lineup. If I were in the market, I would haunt the Test Equipment forum to find out. The Siglents have been around for a while, it could be they are cleaned up as well. In any event, the bugs usually turn out to be in some obscure feature you are unlikely to use any time soon.

author: tautech
author_rank: Super Contributor
timestamp: October 07, 2020, 12:18:02 am
content: Quote from: rstofer on October 06, 2020, 10:15:27 pmNo such model has been available in the west only the 2ch 200 MHz SDS1202X-E.QuoteVery true, remaining bugs for these popular models are very low.Still, scope selection need not only based on price or remaining bugs but specifically datasheet specifications where proper analysis can be a challenge for the scope novice.This is what the forum is for so you can fire questions at us for detailed replies to why one brands spec might be better than another.

author: srb1954
author_rank: Super Contributor
timestamp: October 07, 2020, 12:23:11 am
content: The Tek catalog says 35W maximum power consumption for the 2235

author: tautech
author_rank: Super Contributor
timestamp: October 07, 2020, 01:30:20 am
content: Quote from: srb1954 on October 07, 2020, 12:23:11 amThat's excellent for an old scope and pretty much equivalent to most modern DSO's.

author: Fungus
author_rank: Super Contributor
timestamp: October 07, 2020, 01:52:16 am
content: Quote from: rstofer on October 06, 2020, 10:15:27 pmThe Siglent bug thread is alive and well:https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/1675/

author: BravoV
author_rank: Super Contributor
timestamp: October 07, 2020, 05:30:04 am
content: Quote from: BravoV on October 06, 2020, 03:48:14 amQuote from: Wallace Gasiewicz on October 06, 2020, 05:11:11 pmEssentially you're telling us, on sourcing the old analog scope parts, its all depends on one's luck, right ?Owner of few analog scopes my self, and I know well how hard it is to source them, minor parts like knobs or feet, maybe easier to find them cheap or easily get even thru donation, but some unobtainium part, especially popular ones, like for example the notorious U800 chip from popular Tek 2x65 A/B/vanilla scope, even its available, usually/mostly sellers will put a bastard price.

author: BravoV
author_rank: Super Contributor
timestamp: October 07, 2020, 06:09:30 am
content: Quote from: rstofer on October 06, 2020, 10:15:27 pmProblem is at most scope noobs, they don't even know what a "single shot" is, and it's MAJOR advantages compared to analog scope no matter how super duper cool they are.The words "single shot" admittedly sound very boring, trivial and less eyes catchy.And with this lacking, usually will make a fatal decision unknowingly, that later will haunt the owner after seeing why other people using cheap DSO can see clearly a signal, even at sub Mhz non repetitive signal, which most electronics beginners are dealing with.To beginners, "single shot" means ... using today's popular new generation's speak.. its like seeing your measured signal in bullet time and "STOP/FREEZE" it.And no, you can NOT do that even at the best analog scope ever made on earth.

author: Fungus
author_rank: Super Contributor
timestamp: October 07, 2020, 06:29:57 am
content: Quote from: BravoV on October 07, 2020, 06:09:30 amYep. The advantage of a DSO isn't that it's smaller and has a TFT screen. It's that it can record a signal and analyze it.Analog 'scopes are pretty, for sure, but they're not as useful as a DSO.

author: BravoV
author_rank: Super Contributor
timestamp: October 07, 2020, 06:43:38 am
content: Quote from: Fungus on October 07, 2020, 06:29:57 amAlso in the context of screen sizes comparison, popular DSO vs "popular & well known" analog scope.Here below photo of my Rigol DS1104Z (which has the exact identical physical with DS1054Z) stands on top of my Tektronix 2465B analog (which many considered the best portable analog scope ever made, cmiiw).

author: Electro Fan
author_rank: Super Contributor
timestamp: October 07, 2020, 02:37:08 pm
content: Quote from: BravoV on October 07, 2020, 06:43:38 amThat’s a good view. Might also be instructive to show the same two scopes stacked just like that but from the top down, and from the sides, and from the rear, and also give the weight specs. I enjoy and occasionally use 3 Tek analog scopes but the 1 DSO gets ~80% of the use. Portable for a vintage Tek scope and portable for a modern DSO are two different things.

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2020, 03:34:01 pm
content: Quote from: BravoV on October 07, 2020, 06:43:38 amScreen size, as shown in your picture, is almost irrelevant.Far more important are resolution, readability, what is shown on the screen, refresh rates, etc etc.

author: rstofer
author_rank: Super Contributor
timestamp: October 07, 2020, 03:44:27 pm
content: Quote from: tautech on October 07, 2020, 12:18:02 amApparently, I picked up an offer from Hong Kong by mistake. I'm pretty sure they would ship to the US but what's the point?There IS an SDS 1102-X (no E) available in the US at Amazon but there is no point in confusing things:https://www.amazon.com/Siglent-Technologies-SDS1102X-Digital-Oscilloscope/dp/B01410O5D2The item says it ships from Amazon but since it takes 10 days to get here, I'm not sure where it is actually shipping from.I'm still thinking that the SDS 1104X-E unlocked for 200 MHz is the way to go. In my view, the 4 channel capability is now a requirement whereas in the old days it wasn't even an option.Alas, I won't be in the market for a new scope any time soon.

author: nctnico
author_rank: Super Contributor
timestamp: October 07, 2020, 05:27:51 pm
content: Quote from: BravoV on October 07, 2020, 06:09:30 amYou can. There are analog storage oscilloscopes. But this is just semantics. Nobody should consider buying an old analog oscilloscope as their first oscilloscope nowadays. Even the really cheap DSOs offer much more functionality.

author: tautech
author_rank: Super Contributor
timestamp: October 07, 2020, 06:24:25 pm
content: Quote from: rstofer on October 07, 2020, 03:44:27 pmRisky in that it might arrive with only a Chinese UI.QuoteYep, SDS1102X is the predecessor to 2ch SDS1202X-E model with the faster Xilinx processor but in the race to compete on price the 50 ohm inputs and 8" display were dropped which is why this model is still available.The SDS1202X-E is a far more capable scope.QuoteCertainly, I got a pre-release build that I still have and use frequently today and it still amazes me the capability that's been shoehorned into this fine little package.Both the 2ch and 4ch X-E's sell well here in NZ.

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2020, 07:58:27 pm
content: Quote from: BravoV on October 07, 2020, 06:09:30 amYour knowledge and/or imagination is lacking.Not only CAN you do that, I did it repeatedly and successfully.While I like analogue scopes, analogue storage scopes always were a pain in the ass, not least because having a dual beam CRT was advantageous.As soon as digitising scopes became available, people dropped analogue storage scopes as fast as they could. But for quite a few years analogue storage scopes hung on because of the pisspoor speed/resolution of ADCs.

author: bdunham7
author_rank: Super Contributor
timestamp: October 07, 2020, 08:12:14 pm
content: Quote from: nctnico on October 07, 2020, 05:27:51 pmAnd scope cameras.

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2020, 08:28:50 pm
content: Quote from: bdunham7 on October 07, 2020, 08:12:14 pmThank you for reminding me of those. Not.

author: 0culus
author_rank: Super Contributor
timestamp: October 07, 2020, 10:14:37 pm
content: Quote from: BravoV on October 07, 2020, 06:09:30 amYeah, no. Oscilloscope photography was pretty highly developed back in "the day". HP and Tek catalogs had entire sections devoted to cameras and accessories, as well as application notes on the matter. Now would you choose to do this today if you had other options? No, of course not, but let's not pretend that using a 'scope for single shot is some kind of 21st century invention.That said it might be a fun project to get an old scope camera and retrofit it with a digital camera.tgzzzz will love that.

author: tautech
author_rank: Super Contributor
timestamp: October 07, 2020, 11:01:25 pm
content: Quote from: 0culus on October 07, 2020, 10:14:37 pmOh come onThere’s no way any old legacy equipment allows the complex trigger conditions that a modern DSO offers let alone once those conditions are met the capture remains on the display indefinitely to be examined at leisure and/or saved at will.

author: 0culus
author_rank: Super Contributor
timestamp: October 07, 2020, 11:16:23 pm
content: Quote from: tautech on October 07, 2020, 11:01:25 pmUhhh...that's what the camera was for...?-hp-even had scopes with built in strip chart recorders.If you had readallof what I wrote instead of blasting off into space with hyperbole, you would note that I mentioned that one would not choose to do things this way today. Innoway am I saying that oscilloscope photography is somehow better than a modern 'scope with advanced triggers and single shot acquisition. The point is to dispel the myth that single shot acquisitions were not possible in the bad old days, nothing more. OF COURSE the modern tool is better for this.As to your other point, here's some examples from the-hp-1965 catalog I just pulled off my shelf:

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2020, 11:49:47 pm
content: Quote from: tautech on October 07, 2020, 11:01:25 pmYou mean thissamplingscope didn't do that?Shame the paper is unobtanium, so nowadays you have to use the X-Y pen plotter output shown in the next picture. And note the date!Go on, try that with the a Siglent

author: Fungus
author_rank: Super Contributor
timestamp: October 08, 2020, 01:52:59 am
content: Here's an example of a repair:Note the amount of components inside, tools needed (including other oscilloscope), etc.

author: BravoV
author_rank: Super Contributor
timestamp: October 08, 2020, 02:06:28 am
content: Quote from: 0culus on October 07, 2020, 10:14:37 pmLike this ?This is my setup.And the result ...But c'mon guys ...

author: David Hess
author_rank: Super Contributor
timestamp: October 08, 2020, 02:56:10 am
content: Quote from: rstofer on October 06, 2020, 10:15:27 pmI agree; that is why I bought a 30+ year old Tektronix 2232.(1)Quote from: BravoV on October 07, 2020, 06:43:38 amWhat is not shown in your photograph is that the Tektronix DSOs of that age with that same size CRT have a higher resolution and DPI than a Rigol DS1104Z. 800 x 480? Please. They also produce 16 bit results to take advantage of it. Tektronix was selling "retina" displays more than 2 decades before Apple.(1) I am not recommending that anybody buy an old DSO instead of a new one, which I have done several times now, unless they know what they are getting into.

author: SilverSolder
author_rank: Super Contributor
timestamp: October 08, 2020, 03:23:45 am
content: It's interesting, whenever young people visit my "man cave" / electronics den the first time, they are often completely awestruck by green CRTs, orange plasma displays, large amounts of twirly buttons and dials, and so on... and totally ignore any modern LCD displays that happen to be on... things can go full circle, getting so old they become cool again! (Hoping for it to happen to me now!)

author: rf-loop
author_rank: Super Contributor
timestamp: October 08, 2020, 11:31:41 am
content: Quote from: BravoV on October 08, 2020, 02:06:28 amBut is it so that your setup is missing something what we also have in old times for single shots.And I do not mean memory CRT. Memory CRT problem is that even fastest have quite slow drawing speed (and if everyone in lab use these, mostly some o0f them then destroy this tube due to total lack of knowledge how to use these. Same with micro channel tubes).But what important is missing in your image or least I do not see it.Camera "trigger". Camera need be sync with scope trace draw if want capture single shots. Many Tek and HP scopes have this feature. Also some times fast writing CRT with some very fast phosphor.But yes, nice image, perhaps technically back light level bit too high, it is masking too much some rising edges... (but if think just art... perhaps ok)These Tek scopes have very nice CRT because its surface is flat and back lighted # is deeply inside CRT surface, near phosphor so not high parallax error.

author: David Hess
author_rank: Super Contributor
timestamp: October 08, 2020, 12:10:07 pm
content: Quote from: rf-loop on October 08, 2020, 11:31:41 amNot all storage CRTs were slow; the image-transfer type were fast enough to support bandwidths to 100s of MHz.

author: mawyatt
author_rank: Super Contributor
timestamp: October 08, 2020, 07:21:52 pm
content: Also I recall Tek had some scopes that used Charge Coupled Chips (CCDs) called Bucket Brigade Devices which sequentially captured the analog signal, and not used as an imager. The CCD chip would be read out at a slower rate and digitized with a slower ADC. Good for capturing short period single or infrequent events like fast glitches.Nice Tek scope image, very artsy indeedReminds me of the old Tek scope hoods & camera that used Polaroid filmBest,

author: Vestom
author_rank: Regular Contributor
timestamp: October 08, 2020, 07:39:02 pm
content: Quote from: rf-loop on October 08, 2020, 11:31:41 amYou do not need to sync with camera shutter. In fact, I seriously doubt any camera shutter would be fast enough for that anyway...You just need to keep the shutter open until the scope has trigged and the single shot is captured - while keeping your lab dark! That is also the likely explanation for the over-exposed reticule.But well, time has moved on...

author: SilverSolder
author_rank: Super Contributor
timestamp: October 09, 2020, 01:39:46 am
content: Quote from: Vestom on October 08, 2020, 07:39:02 pmAre you saying, I can clear out the dark room and use it for something other than photography???

author: tautech
author_rank: Super Contributor
timestamp: October 09, 2020, 02:15:10 am
content: Quote from: SilverSolder on October 09, 2020, 01:39:46 amMaybe but keep it dark for a certain well known brand and model DSO that has a dim display.

author: rf-loop
author_rank: Super Contributor
timestamp: October 09, 2020, 02:50:55 am
content: Quote from: David Hess on October 08, 2020, 12:10:07 pmYes I forget these bit more rare things.

author: rf-loop
author_rank: Super Contributor
timestamp: October 09, 2020, 03:20:28 am
content: Quote from: Vestom on October 08, 2020, 07:39:02 pmYes. This is why I write "trigger" and not trigger. Example with TEK 7000 series, single trig sweep mode you start pushing camera shutter open. It give signal to scope trigger system for enable next trigger. After it have trigged scope gate signal give info to camera for close shutter.Camera body is fixed to front of CRT (between camera and CRT is now "darkroom" so no need dark room. Of course these scope camera can also take image fully manually. Also there is mirror system so that user can look CRT when camera is fixed front of CRT so no need all time take camera out and again insert. Time ago, due to lack of enough storage room anymore, I sold out my whole lot of working Tek 7000,s scopeswith couple of plug ins. There was also one -54 with digitizer + "signal analyzing" keyboard and one model what have real dual beam CRT etc etc. I did not find this scope camera and even now I do not know where it is - sadly it have disappeared, it was mint (or better) condition.. (of course not need today for anything but nice piece of history)

author: 2N3055
author_rank: Super Contributor
timestamp: October 09, 2020, 06:25:09 am
content: Quote from: SilverSolder on October 09, 2020, 01:39:46 amWhat do you mean. That is photography too..

author: David Hess
author_rank: Super Contributor
timestamp: October 11, 2020, 12:39:18 am
content: Quote from: mawyatt on October 08, 2020, 07:21:52 pmI have one and they work exactly as you describe. Tektronix made CCD based DSOs for a long time where maximum sample rate on all channels simultaneously was desired and they were more than competitive with ADC and SRAM based DSOs.The Tektronix TDS600 series were all CCD based and peaked at 3 GHz bandwidth, 10 GS/s, 120k sample record length, and 100 ps peak detection.

author: nctnico
author_rank: Super Contributor
timestamp: October 11, 2020, 01:08:59 pm
content: Quote from: David Hess on October 11, 2020, 12:39:18 amIIRC the Tektronix TDS600 series don't have peak detect and no such long records. This series is made for single shot acquisitions at maximium samplerate which makes them pretty limited for general purpose use.

author: rf-loop
author_rank: Super Contributor
timestamp: October 11, 2020, 01:34:06 pm
content: Quote from: nctnico on October 11, 2020, 01:08:59 pmAnd due to trumpeths aka alternative truths, fact check: TDS694C have 500 - 30k record length and Optionally 120k.

author: ledtester
author_rank: Super Contributor
timestamp: October 11, 2020, 02:26:40 pm
content: Quote from: PurpleAmaranth on October 02, 2020, 11:13:39 pmFor a beginner I would suggest getting an Analog Discovery. If you're patient you can pick up the original one (the Analog Discovery 1 or what Digilent calls the "Legacy") on ebay for around $100 + $25 for the BNC adaptor.You'll get a dual channel 20+ Mhz scope, analog waveform and digital pattern generator, 16 channels of digital I/O and a 16-channel logic analyzer.But the real value is the software which coordinates all of these functional units together to create various lab instruments. You can also write your own control programs in Python and I believe Javascript.And there's a fair amount of tutorials, courseware and lab exercises you can find online.And, of course, it doesn't take up a lot of desk space.

author: nctnico
author_rank: Super Contributor
timestamp: October 11, 2020, 05:08:13 pm
content: Quote from: rf-loop on October 11, 2020, 01:34:06 pmOTOH the TDS644A only has 2000 points per channel and no peak detect. The higher end models (TDS684C) top out at 15kpts and still no peak detect. The bottom line is: from the TDS500, TDS600 and TDS700 series the TDS600 is by far the worst choice for use as a general purpose oscilloscope.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 11, 2020, 05:25:12 pm
content: Quote from: ledtester on October 11, 2020, 02:26:40 pmIf you are located in the US, there are two Analog Discovery kits for sale on Offerup (their supply was drained for several months, thus these may be good alternatives).

author: bdunham7
author_rank: Super Contributor
timestamp: October 11, 2020, 05:47:41 pm
content: Quote from: nctnico on October 11, 2020, 05:08:13 pmI haven't had one so I can't say whether they are a bad choice or not, but the specs David posted for the best model, as expected, appear to be accurate--including peak detect.

author: nctnico
author_rank: Super Contributor
timestamp: October 11, 2020, 06:30:08 pm
content: The spec sheet I found for the TDS684C didn't list peak detect but either way if you look at the TDS500 / TDS700 series you'll find these all have peak detect (and high res mode as well). But it doesn't matter much anyway because these series are very old. I have owned several scopes from these series but nowadays I wouldn't bother.

author: Martin72
author_rank: Super Contributor
timestamp: October 11, 2020, 08:58:39 pm
content: Quote from: nctnico on October 03, 2020, 12:06:19 amI would recommend it because it works stable and is long enough on the market, to have it nearly bug-free what the important funtions concerns.The 50Mhz version cost about 349$/365€ and is easy to hack it up to 100Mhz bandwith and deeper memory.Plus lots of math, a good variety of trigger functions, etc.So for 349$/365€ you got a scope with 100Mhz bandwith, 28Mpts memory, advanced math and trigger functions, decode functions.Which scope costs less and got more ?

author: nctnico
author_rank: Super Contributor
timestamp: October 11, 2020, 09:48:42 pm
content: Quote from: Martin72 on October 11, 2020, 08:58:39 pmDepending on where you live the GW Instek GDS1054B is on par price wise and has a more modern & faster hardware platform. This has been brought up before so you are kind of proving my momentum point.

author: Martin72
author_rank: Super Contributor
timestamp: October 11, 2020, 11:23:54 pm
content: Hi,GW intek I´ve known as a c-brand so far.(we got some frequency generators from this brand)And searching this model you named, it seems to change nothing about this.It costs 465€ in the cheapest way in germany, 100 bucks more than the rigol.I´ve never worked with this, so I could only compare it´s features against the rigol.And it losts against the old fashioned one..On the paper, in practice I would like to see a comparison vid from both.

author: David Hess
author_rank: Super Contributor
timestamp: October 12, 2020, 01:24:12 am
content: Quote from: nctnico on October 11, 2020, 06:30:08 pmYou sometimes have to dig into the documentation of each model to find details which I did several years ago when evaluating DSOs for purchase. The early TDS600 series lacked peak detection but later ones include it like the predecessors to the TDS600 series did. How peak detection is implemented on a CCD is an exercise left to the reader.QuoteI have a predecessor to the TDS600 series with peak detection and it works fine. But I agree and do not recommend such old DSOs, although they do compare favorably, even the CCD based ones, with modern DSOs in many respects.I would definitely recommend a TDS500 or TDS700 model which supports DPO operation and segmented memory over a TDS600 model. They can all support phase and magnitude FFTs though which is what I would prefer in a modern DSO and am still looking for.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 12, 2020, 01:53:07 am
content: Quote from: Martin72 on October 11, 2020, 11:23:54 pmGW Instek has some reasonable products and it seems they keep up with some models, particularly oscilloscopes. The GDS1054B is based on the same platform as the SDS1104X-E from Siglent - however, while the Siglent always supported protocol decoding on its full memory, it took a while for GWI to add this feature and, even still, it limits the sample memory to meagre 100kpts in decode mode (according to a user).Here in the US the price difference between the GWI and the Siglent is more dramatic, which favours the former if you are cash strapped.

author: Fungus
author_rank: Super Contributor
timestamp: October 12, 2020, 05:59:31 am
content: Quote from: Martin72 on October 11, 2020, 11:23:54 pmIt's definitely better than the Rigol now that Instek has added all the serial decoders and other features to it. Numbers on paper don't tell you everything. In the USA you can get them really cheap so it's a no-brainer. Things aren't so clear over here.

author: Golds
author_rank: Contributor
timestamp: October 12, 2020, 07:19:05 am
content: It is not recommended that you choose an oscilloscope that is too old, because you cannot predict that it will suddenly malfunction

author: SilverSolder
author_rank: Super Contributor
timestamp: October 12, 2020, 02:35:51 pm
content: Quote from: Golds on October 12, 2020, 07:19:05 amThere is some truth to that - but many hobbyists and professionals use high quality equipment from the 60s - 00s that is still alive because it is repairable.As a hobbyist, I think it would be fair to say I have learned more from poring over old schematics and fixing old equipment than any other way!I would say, instead, that if you decide to go with older equipment, try to pick stuff that is popular e.g. in the eevblog community, so there is a chance of getting answers to questions you may have. Actually that's probably true for new equipment as well!

author: george.b
author_rank: Frequent Contributor
timestamp: October 12, 2020, 07:06:41 pm
content: Quote from: SilverSolder on October 12, 2020, 02:35:51 pmI find this often-repeated fact of greater repairability with older gear to be, while not untrue, overstated, and therefore potentially misleading. All is fine and well until you run into a defective ASIC, or a very hard to get component. Tunnel diodes, or Tek U800, anyone?Also, playing games like "spot the shorted tantalum" when there are dozens of them spread across 5 different boards gets old real quick.

author: tggzzz
author_rank: Super Contributor
timestamp: October 12, 2020, 08:25:59 pm
content: Quote from: Golds on October 12, 2020, 07:19:05 amOr, to put it another way, which is worse: something working whichmightbreak and need to be repaired, or something buggy that cannot be made to work to specification?

author: 2N3055
author_rank: Super Contributor
timestamp: October 12, 2020, 10:35:23 pm
content: Quote from: tggzzz on October 12, 2020, 08:25:59 pmNot even worst digital scopes of today have any problems in anything that analog scope can ONLY do..Even the worst ones will show signals on screen, have functional timebase and vertical channels...Problems, if there are any, are in features analog scopes don't even have...And "digital scopes are buggy" is blown out of proportion... After short time they come out at the market, they get fixed and then are fine.. For instance, Siglent SDS1104x-E, most reported big bug is that it doesn't support spaces in Wifi access point name...As I said many times, advising beginners to purchase 40 years old scope in unknown state is at best naive..You cannot have 40 year old analog scope as your first and only scope as a beginner.Beginners don't have knowledge, other equipment, parts, to verify, repair and maintain those.Analog scopes is expensive and immersive hobby, sometimes enough by itself.If you have enough money, and like to have analog scope (for whatever reason), make sure to have a primary working digital scope (or another working analog scope) to be able to keep it running. And after you count all the money spent over the years, buying new, working digital scope with warranty will look as good deal..My advice, if you're beginner, run away as fast as you can from an old analog scope as your first and only scope. If you can get working one for free or very little money, by all means, take it. But don't pay money for it that would buy you new Rigol or Siglent... That is, if you want scope to be tool to serve you, and you can trust it to work as specified..

author: SilverSolder
author_rank: Super Contributor
timestamp: October 12, 2020, 10:43:32 pm
content: Quote from: george.b on October 12, 2020, 07:06:41 pmThe nice thing is that the old machines were not engineered or built with planned obsolescence in mind. Finding a shorted tant using a toner, milliohmmeter, or other current tracking tool isn't that hard? And they don't blow as often as their reputation would have you believe... I have seen exactly one blown tantalum cap in my entire pile of old tech, and it was the reason for that particular instrument going cheap on eBay as a non-working unit. It just isn't something I'd worry about.Absolutely you can get in trouble finding parts for an older piece of equipment. But typically, the things that fail in older equipment is not the fancy unobtanium stuff, instead it is the usual drying capacitors, failed power transistors, hot resistors drifting out of spec, bad solder joints, etc. - It can get a bit tricky to find exact matches for old semiconductors, but usually there is an acceptable modern substitute.Worst case, you buy another one on eBay and use for spare parts. It is in any case super useful for fault finding to have a working unit to compare to![Edit: @2N3055 is right above, if you are a beginner just get one of the many excellent and cheap modern scopes. But do buy the occasional old bit of gear just for fun, don't switch it on, take it apart!]

author: Martin72
author_rank: Super Contributor
timestamp: October 12, 2020, 11:00:52 pm
content: Quote from: Fungus on October 12, 2020, 05:59:31 amWhich are ?

author: tggzzz
author_rank: Super Contributor
timestamp: October 12, 2020, 11:26:49 pm
content: Quote from: 2N3055 on October 12, 2020, 10:35:23 pmNo more so than "all old scopes are broken"QuoteStrawman argument. Nobody has suggested that.QuoteAbsolute nonsense.Having taught beginners, they understand them better than to complex modern scopes with subtle and important config setting buried in a menuing system.QuoteIs valid from one limited viewpoint.

author: 0culus
author_rank: Super Contributor
timestamp: October 12, 2020, 11:31:43 pm
content: CROs, due to the exact relationship between the crt trace and the input, have a level of tactile-ness that DSOs can't match. This is really important for a beginner. Running a modern scope is a LOT easier if you know how to run a CRO. Well, cussing the damn thing because of the menus aside. I &%#$ing hate menus. This is part of the reason I choose to use old scopes and spectrum analyzers in my personal lab.

author: george.b
author_rank: Frequent Contributor
timestamp: October 13, 2020, 12:19:33 am
content: Quote from: SilverSolder on October 12, 2020, 10:43:32 pmNot so in my experience. I've seen lots of failed tantalum caps, exploding or not, in equipment old and (relatively) new.Besides, I don't imagine too many beginners who are looking for their first scope have a milliohmmeter. Failed tantalum capacitors was just an example that occurred to me anyways; older scopes can have a complex construction, with many more parts to fail, and without proper tools, chasing down a failed component can be frustrating, especially to a beginner, and especially when you'd rather be using the equipment for actually getting some work done.QuoteAgain, not necessarily so in my experience. My 2430A had a bad ASIC, in addition to a tantalum cap that had failed enough to drop the rail it was on, but not enough to either explode or trip the overcurrent protection. Another scope I got had a blown HV transformer, which has proven impossible to find a replacement for. Granted, my PM3055 had bad caps and a blown light bulb, that was pretty much it. Other than the disintegrating case plastics, that is. Or the blown RIFA cap, but that's a given. Ah, and a failed power switch.QuoteAssuming you've been graced with living in a place where that's an option, yes? Not all of us have been bestowed such grace.In contrast, repairing three TDS200 series scopes - each with a different set of failures - was by no means the impossible task one'd imagine it would be for a comparatively modern scope, lack of schematics notwithstanding. And believe me, they were in a sorry shape.I agree with what has been said about some scope being better than no scope. My first scope was the PM3055 I mentioned, and that was a far sight better than no scope. However, cost should definitely be weighed in. As I said on my first reply on this thread, if sufficiently cheap, then sure, an analog scope can be a good option. For a beginner in my country, for instance, it can be pretty much the only viable option - a Rigol ds1054z can be had brand new for the equivalent to $700 here, and the secondhand market isn't much help.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 13, 2020, 12:41:38 am
content: Quote from: tggzzz on October 12, 2020, 08:25:59 pmWell, to be fair anything can break, thus the scale tends to move towards the old analog unless you are talking about a new equipment with warranty. If that is the case, the modern entry level (even the ultra bottom of the barrel such as a Hantek or Uni-T) can show a waveform on a screen, despite not meeting specs (or having very poor ones).Quote from: 2N3055 on October 12, 2020, 10:35:23 pmI wouldn't go as far to say "you cannot have", but instead as you correctly point later in your post: if you can get one for cheap, by all means do it. It is better than "no scope". And it does not even need to be analog, but a used Rigol DS1052E or DS1102E for US$100 (or US$150 if in really good shape) is already a great starter (prices for the US used market, as I know other countries may have higher prices for used gear).

author: Fungus
author_rank: Super Contributor
timestamp: October 13, 2020, 01:36:21 am
content: Quote from: Martin72 on October 12, 2020, 11:00:52 pmAll the ones it didn't have before.

author: Fungus
author_rank: Super Contributor
timestamp: October 13, 2020, 01:39:14 am
content: Quote from: george.b on October 12, 2020, 07:06:41 pmYep. Having the schematic available doesn't magically make things repairable.

author: 0culus
author_rank: Super Contributor
timestamp: October 13, 2020, 03:04:41 am
content: Quote from: Fungus on October 13, 2020, 01:39:14 amYeah, because it requires someone to read and understand the schematic.Plus one will learn a lot by fixing things up, and understanding the theory of operation. And there is no shortage of people willing to help in various places online. Ireallydon't get this almost cult-like belief around here that beginners are to be coddled and spoonfed and protected from–God forbid–having to learn to fix old gear.And let's be real, unless an old 'scope is already beat to hell, it is extremely likely that (1) any problems it has are easily fixed and (2) it will serve many more decades in hobbyist service if fixed and cared for. Long after any hard drives and/or flash memory in a modern scope you might no longer be able to get firmware for have stopped working, effectively turning it into a door stop.

author: george.b
author_rank: Frequent Contributor
timestamp: October 13, 2020, 03:32:22 am
content: Quote from: 0culus on October 13, 2020, 03:04:41 amAbsolutely nothing wrong with beginners learning to fix old gear. But there's a difference between someone getting an oscilloscope as a tool for other ends, and someone getting an old fixer-upper oscilloscope as a project in itself - a project which is usually easier to do, by the way, if you already have a functional scope.

author: BravoV
author_rank: Super Contributor
timestamp: October 13, 2020, 03:52:57 am
content: Quote from: george.b on October 12, 2020, 07:06:41 pmTektronix U800 chip ? Easy peasy !Don't you know this thing grows on tree, here my freshly picked U800s.<sarcasm off>

author: george.b
author_rank: Frequent Contributor
timestamp: October 13, 2020, 04:13:49 am
content: Quote from: BravoV on October 13, 2020, 03:52:57 amThat's pretty brutal. What's the story there?

author: srb1954
author_rank: Super Contributor
timestamp: October 13, 2020, 04:38:30 am
content: Quote from: Fungus on October 13, 2020, 01:39:14 amBut it generally makes the fault diagnosis considerably easier.

author: 0culus
author_rank: Super Contributor
timestamp: October 13, 2020, 05:20:20 am
content: Quote from: george.b on October 13, 2020, 03:32:22 amSo? Maybe they want to learn, has anyone in one of these threads ever asked them? Probably not since the OP is usually running away as fast as possible after seeing the argument break out.FYI, I fixed a Tek 585A with a serious short to ground, with nothing but a couple of multimeters and the actual printed manual in hand. Two shorted diodes in the rectifiers for the B+ supplies. Couple of new 1N4007s later it was good to go. Not that I would recommend a beginner be poking around in a Tek tube scope...those B+ supplies will not suffer a moment of stupidity...but you don'tnecessarilyhave to have all the fancy gear to fix stuff. Some basic tools, a desire to learn, a manual, and more experienced folks to get advice from.

author: tautech
author_rank: Super Contributor
timestamp: October 13, 2020, 06:32:35 am
content: Quote from: 0culus on October 13, 2020, 05:20:20 amYeah that's the hard bit, deducing a newbies experience or even their want to dive into the innards of a CRO whereas they might just want to play with basics to look at squiggly lines or 555 timer stuff.QuoteBeen there done that and earned the badges along the way which initially lead me down the road into getting a distributorship where the last few years business has replaced hundreds of CRO's with something more useful for the novice as it's much easier to grab and post a screenshot when seeking advice/mentorship.This screenshot capability primarily led me to DSO's where my first DSO was a Tek TDS2012B, the first in that range that had USB so to make it dead easy.Chuckled with a long time customer today about these old Teks as he still has one but none of his staff want to use it and instead fight over his little Siglent X-E's instead.Amazing to see what he does with these entry level DSO's ......not that I can share much about his IP other than to say it's EV wireless charging over 200mm to the tune of 20kW !

author: 2N3055
author_rank: Super Contributor
timestamp: October 13, 2020, 08:32:54 am
content: Quote from: tggzzz on October 12, 2020, 11:26:49 pmYou and most other analog scopes aficionados seem to take this personally and emotionally.I don't disagree with your decisions for yourself. I couldn't even if I wanted to. They areyourdecisions aboutyourlife.And, to make it clear, I also used analog scopes much longer than I've been using digital ones. I do have nostalgia about them. I love them, the green glow wakes up good feelings and memories of simpler times when things seemed more magical...Butmagicalmachinesthey're not.And,yes40 years analog scopes youcan buy/get todayaremostly broken, most of them quiteliterally.By that I mean exactly that. They are not old junk that rotted because it was bad quality. Quite literally, they were made of gold and all kinds of precious materials, and if they don't have much on hours, they still can have 10s of years in them...But most of them are broken, mechanically, abused, butchered inside for whatever reason. If you can get one that was never badly maintained (butchered inside), not broken mechanically, was kept at room temperature without condensation in clean environment, etc..etc.. You might get one of those mythical beasts you talk about...Butthose specimensare becomingas rare as dragons...... All you can buy now is simply broken crap...Not because they are bad machines (they were excellent quality and made to last), but because in 40 years they were abused, dropped, shocked, connected to wrong voltages, then scrapped, sent to recycle plant, dropped from the back of the truck on the ground, was there on rain for years, salvaged, cleaned a bit and now being sold to you...And, if, by chance a good one appears, getting that one ispure luck.So, yeah, statistically speaking, if you buy analog scope from just anywhere today, you're gonna get crap.And again,beginners.Beginnersdon't have skills to chooseone that is good. Theydon't know howtocheck if it functions right.Theydon't have other equipment needed(calibrators, signal generators...)So they are buying a cat in a bag...If something is wrong they also, have neitherskillsnorequipmentto repair something ascomplicated and sophisticatedas an oscilloscope..That is not something I would recommend to a beginner. That is what I would say to a beginner 20 years ago when there wasn't choice. Scopes where as expensive as a car, and for a hobby, only choice was to get an used old one and hope for the best.Today be we have a better choice. For same money people ask on Ebay for " an excellent condition Tek scope, untested, as is" (that by the way is missing half buttons and knobs), you can buy something that works up to spec, has warranty, and has 20x times more capability that green wiggle machine that cannot: freeze capture on the screen, do probe attenuation math, do any measurements aside cursors (if you have advanced model), show slow sweeps, have any other trigger than slope and video (which is of very limited use today), and literally hundreds of other functions..Quote from: 0culus on October 12, 2020, 11:31:43 pmI couldn't care less for "tactile-ness". I don't have scope to "gently stroke it's buttons in a bliss".It's an instrument. It should do its job. My job is to learn how to use it.Running a DSO is much easier if you NEVER used CRO. Most of the stupid questions, misunderstanding, and those annoying whinings (this scope is so baad, because they don't call it same as Tek did...) are from people coming from CRO. To learn to use DSO effectively, you need to learn different ways how DSO is used, instead of whining how "things are not as they are supposed to be"...Those that learn on DSO simply learn how it works from the beginning and get on with it... And on DSO, they learn vertical controls, timebase, basic trigger so quickly (that is all they can learn from CRO), not many questions are about that. They learn all that in few days.Questions are about FFT, or measurements or digital triggers.. All the stuff that CRO cannot teach them because it doesn't have it.And some DSO even have demo signals that you can use as small course to learn how to use it. I used those with my son (on a 3000T) and it was very helpful.As a side note to all DSO manufacturers: " Yo idiots, that demo board shouldn't cost 250 USD. It should be 20 USD, or free, and make 20 pages PDF with short course. For example see how Keysight, and R&S does it on some of their scopes."My son literally learned to use Micsig STO1104C in two hours.... than second day we spent few more hours on details of persistence, display modes, decodes... With Keysight 3000T it is not that simple, because it has hundreds more functions. On that one I simply have manual handy. I consult it sometimes about details. I make it a point not to learn by heart anything that I don't use all the time.Truth is, lots of that advice about CRO scopes was still good advice maybe 10 years ago.. But it isn't anymore. In meantime, world changed a lot. It's time to move on... And CRO scopes are going the way of TTL based arcade game, retro Z80 computing, etc.. If you like that stuff, that is great. I love it too.But IBM PC XT is not something I would recommend to friend as an answer to question:"My friend: Hey, Siniša, you know this computer stuff...I have no clue about this, but I would like to learn programming in C. What computer you would recommend me to buy to get me started. I want something small and simple and cheap..Siniša: Well, my friend, there is this cute little thing called Raspberry PI.........."I'm sure you do get this analogy.. And it isveryaccurate...Regards,Siniša

author: David Hess
author_rank: Super Contributor
timestamp: October 13, 2020, 08:36:35 am
content: Quote from: 0culus on October 12, 2020, 11:31:43 pmI disagree; there is nothing which prevents a DSO from responding to user controls with a latency of one display frame, which is fast enough to be visually indistinguishable, except poor design.

author: tv84
author_rank: Super Contributor
timestamp: October 13, 2020, 09:10:41 am
content: Quote from: David Hess on October 13, 2020, 08:36:35 amNitpicking a little: even with 120Hz/144Hz displays the human eye can see the difference.Nitpickings aside, I disagree with you. There are a lot of things being done by the processors/FPGAs nowadays to stop that from happening, in "economical" terms. Unless you specifically build a gaming DSO. In that case, with the right money poured into the design, sure you can have those latencies.

author: tggzzz
author_rank: Super Contributor
timestamp: October 13, 2020, 09:54:04 am
content: Quote from: 2N3055 on October 13, 2020, 08:32:54 amYou knownothingabout my background and experience, nor my views on digitising and digital scopes. But that seems not to stop you shouting your preconceptions in a long rant that I've omitted for everybody's sanity.For the record I've been using digitising scopes for >40 years and digital scopes for >30 years. I've also had long discussions with the person who had (and was continuing to) design HP's high-end digitisers.I am perfectly happy to use a decent digitising scope; the modern ones do their job well, even if there are extra subtleties that catch out the unwary.

author: Fungus
author_rank: Super Contributor
timestamp: October 13, 2020, 10:11:00 am
content: Quote from: 0culus on October 13, 2020, 03:04:41 amSome people want to get other things done apart from fixing their test gear.Quote from: 0culus on October 13, 2020, 03:04:41 amBut modern 'scopes can do moreandthey fit inside modern apartments.If you grew up with that old gear then I understand that there's a certain fondness for it. Those old 'scopes emit a reassuring smell as they heat up, etc., but a youngster won't have that nostalgia.

author: 2N3055
author_rank: Super Contributor
timestamp: October 13, 2020, 10:23:15 am
content: Quote from: tggzzz on October 13, 2020, 09:54:04 amI don't know anything about you except what you write here on the blog...All I see is you recommending how great idea is to push an analog scope at unwary beginners "because it is good for their soul" or whatever..Length of my rant is not even close to being proportional to how many times i hear this utter nonsense being repeated in this day and age..And I didn't mean to offend YOU... Being analog scope aficionado is same as being gourmet food aficionado: nothing wrong with that, it actually points to good taste and wast knowledge of the topic. It becomes inappropriate, when such person gives truffles recipes to person that cannot afford food. It is not wrong, it is not from bad intentions, it is just not helpful to a person in question.And as I read many of your posts (most of them being pure gold) i do believe you know very much about every type of scope there is in existence.. In fact, you know so much, that you forget how little beginners know... You know, those people that find single transistor amplifier overvelmighly complicated... I know, I'm sure guilty of that too.So, it's not my intention to aggravate you, or belittle iota of your knowledge..It's just, fact is, old analog scopes are museum pieces. If you're lucky to have specimens that work well, and you enjoy using them, lucky you.They reached status of oldtimer cars. Sure there are many vintage cars people keep running and eve use as daily drivers.Old vintage car might be a good car for a beginner mechanic. Not for a beginner driver.Good first cheap computer for beginner programer is Raspberry PI, or any cheap moden PC, not vintage IBM PC XT, good first car for beginner driver is few year old small Toyota Yaris bought with at least minimum warranty, and good first scope for an absolute beginner is cheap modern DSO.Regards,Siniša

author: SilverSolder
author_rank: Super Contributor
timestamp: October 13, 2020, 02:44:27 pm
content: Quote from: 0culus on October 13, 2020, 03:04:41 amDoesn't it all depend on the beginner? It's like with cars: Some guys are better off buying a new car, if they are more interested in driving than fixing cars. They might be inept at fixing cars, yet be a pretty good driver... and vice versa! Or, consider the relationship between a pianist and a piano tuner...In other words, a good decision could mean either buying a new or a used scope, depending... on you!

author: BravoV
author_rank: Super Contributor
timestamp: October 13, 2020, 02:50:57 pm
content: Quote from: george.b on October 13, 2020, 04:13:49 amLOLyeah, it was bought many years ago from Israeli's seller that sell T&M equipments that looked like they're ran over by tank in war zone.I was lucky on the timing, that the seller was going to close their shop put everything on big sale, and offered me these gems for a good bargain.

author: tggzzz
author_rank: Super Contributor
timestamp: October 13, 2020, 02:59:23 pm
content: Quote from: 2N3055 on October 13, 2020, 10:23:15 amYou are fantasising.Please indicate where I have advocated that position - or don't make such statements.QuoteMore passive-aggressive nonsense.There are far more things that I don't know than I do know. I temper my statements to reflect that.QuoteExceptIteach absolute beginners how to use a scope.QuoteThat is your prejudice.A working scope is useful, no matter what its age.QuoteMore nonsense and unhelpful analogies.If you want such analogies, try using aircraft - where many 1950s/1960s/1070s aircraft are used to train ab-initio pilots due to their excellent and predictable handling characteristics.

author: PixieDust
author_rank: Frequent Contributor
timestamp: October 13, 2020, 03:12:05 pm
content: My second hand Tek scope has a bad pot, so sometimes I have to reboot it (can you reboot an analogue scope?). Plus I had to replace some caps that blew. So second hand is certainly not free of problems.

author: 0culus
author_rank: Super Contributor
timestamp: October 13, 2020, 03:23:48 pm
content: Quote from: BravoV on October 13, 2020, 02:50:57 pmOh man, I remember that seller. Everything looked like it had either been driven over or in a shipwreck. So bizarre.

author: 0culus
author_rank: Super Contributor
timestamp: October 13, 2020, 03:24:45 pm
content: Quote from: SilverSolder on October 13, 2020, 02:44:27 pmThat's exactly the point I was trying to make! This forum has a "one size fits all" mentality on this subject in particular, and it's!!

author: 0culus
author_rank: Super Contributor
timestamp: October 13, 2020, 03:27:15 pm
content: Quote from: David Hess on October 13, 2020, 08:36:35 amMy point still stands, however, because the only DSO I've used where that is the case are MegaZoom models from HPAK. Everything else has enough latency between twiddling the rotary encoders and seeing the update on the screen that it is quite jarring.

author: 0culus
author_rank: Super Contributor
timestamp: October 13, 2020, 03:30:40 pm
content: Quote from: Fungus on October 13, 2020, 10:11:00 amBut I didn't grow up with old gear, and I still have a nostalgia for well made equipment that was built to last. And I use mine on the daily whilst also being fully prepared for troubleshooting if needed.

author: george.b
author_rank: Frequent Contributor
timestamp: October 13, 2020, 04:09:13 pm
content: Quote from: BravoV on October 13, 2020, 02:50:57 pmAhh, I remember that one, I think. From eBay, right? He had some stuff in atrocious conditions alright. Didn't know they had closed up shop.

author: SilverSolder
author_rank: Super Contributor
timestamp: October 13, 2020, 04:40:38 pm
content: Quote from: 0culus on October 13, 2020, 03:27:15 pmThat's easy to fix - Only use HPAK scopes!

author: David Hess
author_rank: Super Contributor
timestamp: October 13, 2020, 08:27:35 pm
content: Quote from: 0culus on October 13, 2020, 03:27:15 pmIt is a design choice of how the controls interact with the waveform acquisition and display process.For instance on old and slow Tektronix DSOs like the 2232, the analog position control works like an analog oscilloscope and updates instantly like an analog oscilloscope, but is also digitized and the software uses the result to update the previously displayed waveform which will not be updated until the next sweep. Tektronix knew user responsiveness was a problem and designed to reduce latency.There is zero reason for user input to not be processed before the next display frame, other than not caring.

author: Neurosurg
author_rank: Contributor
timestamp: June 21, 2022, 10:28:39 pm
content: I have a big pleasure working on RTO200 which I bring from work (Physics Institiute) to home, asking for something a bit powerful than MDO3054 I have. Recived a big suprise.I'm working at Phisics Institiute at the University, as a science aparature electrionics, reparing and improving e.g. electron microscopes, ionisation vaccuometers etc. and creating new stuff driectlly to sophisticated reasearch set, unable to buy all of the World.Before I have a little experience with R&S stuff, using mainly Tek, Agilent/Leysight, little bit LeCroy, Rigols, Siglents etc.For now. The R&S scope I found at Our Departament, at magazin, in box. It was HMO1102 unusage ouf of warranty with 1 bad pixel. Story ends in the way I was told "If I wanna I can get it for free"/Firstly I planned to sell it on ebay. But one day interesting push me to open box, and connect this little scope to mains.The impression was more then i expected. Little, dead silence cause it's with no fan inside, working fast, very responivly. Old Vintage component ttester plus pattern gen. sounds great. Possibility to programable enchanced the resolution from 8 stright to the doubile giving 16bits where you really noticed this change not like in Rigol or Siglent, pusching buton cchange the value but on screen no singhts of change.Semi-automated FFT setting algoritm, just set time domain, nr of points, window and Arythmetic mode: Refresh, Average _+ set number of this - beauty reduced noise, or envelope.Is ti possible to add color grade to spectrum. Minus, for changing the time domain you must exit FFT, in FFT time enconder just only adjust of spectrum span.Materials using to create it on huge level, my HMO version was the last made fron 0 to the end in EU.Sa When I need a scope for project from work I choose by blind and rembering the grest work on HMO1102, I ask for some from R&S, actually available was RTO200. Today colluage from work are delivered me it, because I'm post amputatnio from oncology reasons with troubles with wound to closed. So worke from home.Today i only playing with RTO2000, with huge impression.Have you have some from R&S but more then RTC1002 or RTB2004? For private?