EEVblog 1632 - WHY sell 2CH Oscilloscopes? + Test Engineering

[@trapperjohn7571]

In this video: Dave explains why people who can afford 4 channel scopes still buy 2 channel sometimes, and the comments section gets mad at him for not considering that some people can't afford 4 channels Next week's video: Dave explains why a 2 channel scope is still useful for people who can't afford 4, and the comments section gets mad at him for suggesting 4 is a waste of money

[@EEVblog]

Being a KZbin creator summed up in a single comment.

[@mihirsanghvi9876]

So the takeaway here is a 4 channel scope is better but If u can't afford one so it's best to improvise with a 2 channel scope and get the job done

[@EEVblog]

@@mihirsanghvi9876 Obviously.

[@davadoff]

You shouldn’t pay extra for something you don’t need. Even if 20% more money gets you get twice as much product (especially with fast food!). As fast as I can tell, Dave offers no reason to recommend 4ch only, other than ‘it’s only an extra $100’ or whatever. Is it because 4ch might come in handy one day, so you think it’s well worth it for that rare situation? If you only need 1 or 2 channels.

[@EEVblog2]

@@davadoff Sure, don't pay for something you don't need. Where did I say a hobbyist should pay for something they know they won't need? Why are people taking this so personally? As always Your Millage May Vary. In this video I was clearly talking about how things typically work ** in the industry **, it was not a treatise on hobby scope selection. As I have discussed in the Rigol 1054Z and DHO800 videos, 4CH scopes have now become very affordable, and they offer great flexibility in usage scenarios and sample rate split, and as ** a general rule ** I advise getting a 4CH scope even if you think you may not need it. But if you want to save every cent, obviously taking my advice would be dumb, just buy a 2CH scope and be happy.

[@dhombios]

When I started working as a R&D engineer, they gave me the most expensive scope in the lab (it had 4 channels) while experienced engineers preferred the cheaper 2 channel ones. Soon I found that the reason why they preferred those was that the expensive one used windows as its operating system, so it took more than half an hour to boot. Additionally, nobody cared if you accidentally short-circuited the cheap ones, but damaging expensive equipment was a major concern

[@RichardKuivila1947]

They are better than 0 channel O-Scopes !

[@easyBob100]

Otherwise known as a no-scope?

[@teresashinkansen9402]

I have one of those! never had failed.

[@TrickyNekro]

Otherwise known as the finger method 😂

[@norbert.kiszka]

Magic glass ball, always in use. Sometimes its laziness to turn on and connect scope.

[@bflmpsvz870]

@@TrickyNekro I only use tongue in my 9V batteries tests. Call me tongue school.

[@PeregrineBF]

The main reason I have a 4ch scope is because it has two ADCs, where most 2ch scopes only have one. So the bandwidth drops in two when using both channels on a 2ch scope, but I can use one channel from each ADC and still have full bandwidth on both.

[@Dr_Mario2007]

Sometimes I just use one channel on my dual channel oscilloscope for a bit better accuracy especially when sorting out oscillators by their frequency.

[@Peter-rt3tu]

you mean sample rate, not bandwidth?

[@PeregrineBF]

@@Peter-rt3tu Not analog bandwidth, but halving the sample rate halves the Nyquist rate, i.e. the maximum bandwidth signal that can be measured.

[@mrnmrn1]

Also handy for differential measurements. 4 channels gives you 2 differential channels and you don't have to buy external differential probes. The price of two decent diff. probes exceeds the difference between the 2ch and 4ch version of a scope, probably even amongst the higher end scopes.

[@sarowie]

@@mrnmrn1 a diff probe tends to be more accurate then the math function. but offcourse: using two channels also shows the common mode which can also be useful in its own rights.

[@mikesradiorepair]

Honestly I don't "need" 4 channel scopes to repair radios. In reality I could get by just fine with 1 channel scopes. Do I own 2 channel scopes, nope. I always go with the 4 channel version. I usually leave a 1X, 10X and 100X probe attached to each of 3 channels and leave the 4th hooked up to a RF sample port on a directional coupler to view transmit modulation. However, 99.9% of the time I'm only using one channel at a time.

[@Scrogan]

I find two channels at a time is useful for seeing the progression of signals as they pass from one circuit element to the next. Seeing time delay, voltage drop, where noise gets better or worse, that sort of thing. And using a 4 channel scope I’d likely just do the same thing, but I’d be able to make differential measurements too without buying (or making) a differential probe. It’s nice to have three or more signals visible at once, but I think two is all you usually need. For multi-wire comms protocols (three-wire SPI, or RS232 with flow control) yeah you’ll want to see all the wires at once, but that’s what a logic analyser is for.

[@pa4tim]

I do the same, I most times use one probe on my main scope (R&S) but I have always connected a 10x, 20/200x diff probe, current probe and 10x magnetic micro-probe. (and 16 LA probes) This way I do not have to set up the channel and compensate the probe each time I use it. If I need an other probe (1x, 100x, 1000x, 40kV etc) I use one of my other scopes.

[@SuperHaptics]

I do all the sampling with my pinky no need for an expensive 1 channel scope

[@pa4tim]

@@SuperHaptics Good for you, you probably work in the field of free energy 🙂

[@SuperHaptics]

@@pa4tim nice one 😁👍

[@mooserov]

back in the previous century, Army procedures would start with - ' attach probe 1 of your 2 channel oscilloscope to TP13' . These did not really ever change, so when it was time for new test gear -- 2 channel.

[@grizzlyrideemwet1698]

Education also often puts these lab builds out for bids. We want 40 two-channel scopes of 100MHz with .... Lowest bidder meeting the specs wins to sale. And companies want to get their gear in front of future users, so they play along.

[@MsFireboy2]

That’s a pretty standard option in tech schools.

[@ratdude747]

This. Although I did bust out one of the old semi-analog CRT scopes with 4 channels when doing a signal processing lab involving differentiatiors and integrators as 4 channels allowed me to show the input signal and it getting transformed by each stage all on one screen (instead of nice screenshots from the DSO scope, I had literal screen shots with my digital camera of the waveform)... the professor liked it (he was old school!). When equipping a lab with 20+ stations, costs do add (especially when the grant budget also has to cover a buttload of RF gear... which is also very nice!)

[@nonsuch]

New 4-Channel scopes can be had now for as low as $299. It's pretty remarkable.

[@EEVblog]

Crazy

[@MichaelKingsfordGray]

Useless for glitch/runt-catching.

[@nonsuch]

@@MichaelKingsfordGray Useful for the other 99.9999% of things needed.

[@Peter-rt3tu]

@@nonsuch ...as long as they display more or less correct readings. WHat are 4 chanels worth if all of them display just rubbish?

[@nonsuch]

​@@Peter-rt3tu Cheap doesn't mean rubbish. Unless you're one of those people who really believe you get what you pay for and branding has nothing to do with the cost of an item. If you want, I can tell you it costs more if it'll make you feel better about using it.

[@pauldenisowski]

Great video explaining how oscilloscopes are used in test engineering / manufacturing: it is indeed much bigger and more important than many scope users might realize.

[@TeslaTales59]

When it was time to replace my 40 year old Tek CRT scope, I bought a Siglent 4 ch. Was slightly $50 more. Worth it.

[@michaelardai9703]

I often use all 4 channels and wish I had another. Think about having to measure line voltage, current, zero cross, and phase control for a dimmer or pump control, or SPI, or i2c plus an input or output signal, etc.

[@matthewzepess5721]

I’m saving up for a dho804, will end up being my first scope but I did notice very minor difference in price if we’re talking brand new and many want retail for a used unit.

[@EEVblog]

Good choice, it will serve you well.

[@__qqq__]

I was looking for my first scope recently and noticed the same thing (ended up with a decent deal on an almost new SDS1202X-E; would've preferred a 4 channel, but didn't want to wait till something showed up in my budget). I'm guessing it might be because of the supply of analog scopes running dry (at least here, people regularly want $100 for a banged up two channel 20MHz), and the supply of used digitals has not caught up with the demand yet.

[@drkastenbrot]

I have the 914S and its a very neat tool. Big enough to be comfortable to use, but portable enough to not need another portable scope. And with the power input being USB PD you can very easily do an isolated ground setup. Keep in mind that you have to separately ground the scope for normal use though, the included adapter is isolated (as is common with most small power supplies).

[@matthewlewington2470]

Have to say many years ago, I brought my 2 channel siglent scope which I like alot, but it was all my pocket money at the time and though i really wish i had a 4 channel, at the time that's what i could afford and that's what served me well. Saved heaps of time from going back to school to test circuitry modify and home and repeat.

[@KaylansDrone]

I bought my first scope no more than a week ago and went with 2 channels because it was cheaper. However, if i ever upgrade, it will be a 4 channel because even though i never needed more than 1 for most of what i do as a beginner i have already found a reason to use 3 or more.

[@flymypg]

I've never had a large test equipment budget, and as the gear often had to go out into the field, I generally bought used. When I got tired of dead buttons and scratched/cracked screens, I started buying headless LXI and USB o'scopes. Most were 2-channel units, ideally with trigger in/out capability to synch multiple ones together. I'd integrate them with a mid-tier gaming laptop which would provide abundant compute power for real-time calculations and fast storage for effectively infinite data archives. While this was certainly good enough for day-to-day use, the best part was it saved enough money to allow me to get some really good kit for the lab that would NEVER go into the field.

[@notgiven3114]

You are my kind of guy.

[@johnwest7993]

In my career, (40+ years so far) as an R&D and repair tech I've seldom ever needed to use a 4 channel scope, and I've managed to do external triggering using a pair of 2 channel scopes to gather 4 channels of synchronized signals. With a big budget for the lab I'd get a 4 channel, very fast scope. But a faster 2 channel scope is cheaper and is needed 'much' more often than a 4 channel scope except in small subsets of engineering, and almost all common scopes run much slower when gathering 4 channels of info anyway, making the 4 channels only useful for slower signals.

[@py2bnd-sota411]

Shure, bandwidth and sample rate in practice is much more on demand than input channel numbers. I don't remember that I ever needed more than 2 channels.

[@drkastenbrot]

most lower-level scopes use 2 ADCs for 4 channels or even just 1 ADC for 2 channels. When using more channels than the available ADCs, sample rate and bandwidth gets cut in half.

[@py2bnd-sota411]

@@drkastenbrot Right, the sample rate drops to the halve, but normally bandwidth remains.

[@drkastenbrot]

@@py2bnd-sota411 yep, sorry, bandwidth would remain the same as long as the sample rate is sufficient.

[@garyflies]

I work as an avionics repair engineer, we have racks of specialized test equipment, and I mostly get away with using one channel for most calibration work I need to do. I like using X-Y mode for calibrating resolvers (it gives a nice 360 degree pointer on the screen) but thats about the only time i need to use 2 channels. I would never have the need for more channels, therefore we would only purchase a 2 channel scope for our needs.

[@garthhowe297]

I'm am retired, and a home enthusiast. I have five scopes (hmm maybe more hiding), and only one of them is four channel. In my case, I have never used more than two channels. I think you may underestimate what a few hundred dollars means to a home user. I take that cost savings, and use it to buy a model with a larger display... which is something important to me.

[@wembleyford]

yup, this

[@notgiven3114]

I'm a 69 year old designer/tinkerer who doesn't have go to work anymore either. I've been in the electronics engineering (and software development) field since 1974. I'd say that I'm retired, but I've been self-employed for most of my life, and haven't had to to abide by company policies, or share test equipment since the early 1980s. "Retire" doesn't have much meaning in this context. For decades, I've "worked" only on what I wanted to, when I wanted to. One might think that under these circumstances, I'd sometimes want to use a four- or eight-channel scope. But I can't remember a single time when I've wanted to simultaneously use more than two scope channels. I do however have several scopes. But all of them combined cost me less than one medium range modern scope.

[@EEVblog]

Sure, and I said as much, but the difference between say the Rigol DHO800 CH and 4CH is only $110. If you have other requirement that mean more to you then of course you go with that. But as a general rule I now advise people to get a 4CH scope as a minimum as the price premium is nothing like it used to be.

[@notgiven3114]

@@EEVblog Actually, you didn't say as much. And your point in your comment only makes sense if having two more channels is useful to you. In my case, they're not. All they provide is needless clutter.

[@todortodorov6056]

I can spend one or two hundred more. My problem is; this is a toy (with the rest of the hobby stuff) and it needs to be stored away when not used, as the boss (the wife) will give me another warning. So, I want one that is not too bulky. For me; size matters! I will probably never need more than 1-2 channels.

[@gblargg]

A channel input going bad on a 4-channel scope is minor, but devastating on a 2-channel scope.

[@connecticutaggie]

I am a Test Engineer and I do use COTS test equipment for my racks because they have traceable accuracy and are easy to support calibration. That said, I do my best to buy equipment that does not have a UI since all the testing is automated an I don't want to waste the space or cost of the display, knobs, and buttons and I also don't want anyone fiddling with them.

[@Germanwtb]

Just bought one of those rigol rackmount units. It's nice to have something you can use semi remotely in a semiconductor test (i.e. testing wafers straight from the fab) environment. But honestly, I wish they had the normal knobs and buttons just as a Bluetooth controller, for when I don't have everything dialed in and automated yet. The mouse only control, with a fairly low resolution (only 720p!) is a bit annoying.

[@Jeff-ss6qt]

Does the software accept anything like MIDI controllers or a way to adapt one? Those usually have knobs, sliders, buttons, and anything else you could want.

[@nraynaud]

@@Jeff-ss6qt you generally have to send GPIB commands to it, so you'd need to create an adapter.

[@nutsnproud6932]

My ancient tube valve 2 channel twin beam Tex scope still works fine for my audio work.

[@bryanlatimer-davies1222]

I do audio work only, and 2 channels is all I use as well

[@randynovick7972]

True story: I bought my first scope - an analog 20-year-old 2-channel tektronix that was still in-spec (miracles!) - just to do some signals troubleshooting for some dinky radio repair projects I was messing around with. Did just fine for what the need was, but I wanted to get better measurements for some microphone projects. It was October, so I put a couple of the better cheap 2-channel digital scopes on my amazon wish list for XMas, along with a nicer power supply than the janky-dangerous-home-built buck supply I'd been using for ages... and I guess my family got the hint because I got BOTH scopes... and not the power supply. So I DO have 4 channels now, and 2 screens! ... and I spent the rest of my XMas money on the power supply. (sad trombone) The bench got very crowded but I do like having 2 screens. So Dave, the best reason to have cheap 2-channel scopes is so that your relatives can buy them for you when they have no clue what to get you for XMas. Done and dusted!

[@erintyres3609]

As a home hobbyist, I find four channels even more important than high bandwidth. Even if your circuit is just a 555 timer, the extra channels let you see what is happening in four different parts of the circuit.

[@Seiskid]

Seismic acquisition - spent years riding boats - soon as I saw that silver thing I knew streamer module. Comms faults on cables - especially lead ins - was a constant issue.

[@roflchopter11]

5:12 educational institutions should realize that if they buy the 4 channel scopes, they can have their students burn out 2 channels of analog front end before they have to have the scope repaired.

[@video99couk]

7:41 That's the life that my TDS3012 started in. It has the GPIB option because it was programmed to make measurements and feed results back to a PC running a test program written in Visual Basic, around year 2000.

[@evgenygridasov8455]

I've just been to QUT Open Day (Brisbane), and they have a mix of R&S, Keysight and Siglent scopes in their labs. All of their scopes are 4 channel models, I haven'ts seen a single 2ch scope there.

[@EEVblog]

Depends on the requirement, see my tour of UNSW where they have a mix of 2CHand 4CH : kzbin.info/www/bejne/gGTPnKGgpKmHjNksi=K8uoRRoKeARNtBDT

[@todkapuz]

yeah when you get to the test engineering part... I work for a medical device manufacturer and we use oscilloscopes for in-process testing.... for example we have multiple copies of the exact same specialized liquid manufacturing process that requires an off-the-shelf waveform generator and an off-the-shelf oscilloscope to induce and measure a physical phenomenon in the manufacturing process... and yeah... it isn't complicated, it isn't some guy sitting in a lab repairing stuff... but yeah.. absolutely need an exact feature set that can be easily and repeatedly reproduced to allow for quick repair and/or expansion of the lines... and yeah.... there we need 1 channel..... why pay for 4? ... it doesnt help. So yeah... 2 is the few most make, and that's what we bought in bulk last major upgrade. Don't use the probes that come with the scope or anything... that is, as mentioned here... is somewhat specailized by our in-house test engineering group... but thats because it literally is the core of making the product.... but just standard bnc for the two rack-mount gear.

[@jardel_lucca]

Why would buy a 4 channel scope? - Because they don't make with 5.

[@gorak9000]

In very high end scopes, you can get up to 8 channels, but you'll probably have to take out a second mortgage on your house to afford one

[@sarowie]

@@gorak9000 at that point, you take two 4 channels scopes with connected external trigger. Or you realize that you are looking at digital signals that could be captured digitally.

[@gorak9000]

@@sarowie Don't worry, the companies that buy those high end 8ch scopes have DEEP pockets, and the companies that sell those tools to the companies that use them probably use the cost of the scope to partly justify charging over $1M for the tool the scope is used in!

[@qzorn4440]

The new hobby oscilloscopes are getting so wonderful at values prices. A four channel scope is a practical investment. Thank you Dave. On the factory floor a 4 channel scope is nice for 3 phase troubleshooting with all the FVD motor controllers

[@3beltwesty]

In Disc Drive manufacturing at one company we bought 100s of Tektronix 2215 O scopes to use on the manufacturing line.. we use 456 s in the engineering lab . One production test had the line technicians with every drive switching the time base and gain switch every drive tested back and forth. We actually wore out the switches on these "cheapie 1st generation" 2200 series Tek actually set up a vcr camera to videotape what we were doing. Great since maybe this helped them build more robust devices It was impressive to have actual non bs marketing chaps but real engineering folks visit

[@epeglab1o1]

Personally have a 4 ch oscilloscope and when debugging I always found myself wishing for more channels. Can I do my work with less channels, likely yes, but I hate wasting time moving probes or changing probes each time. For anything more complex than 2 port systems, using a 2 channel oscilloscope is painful and the time spent debugging adds up. I think most people who are doing anything complex for home projects all the time are willing to spend the hundred of dollars for a 4 channel unit. People who do smaller projects like keyboards likely don't want to put the cash for it.

[@davadoff]

Maybe you can use a PC sound card type scope to give extra channels for cheap or free. For debugging, would 200KHz bandwidth on some channels be enough?

[@epeglab1o1]

@davadoff unfortunately not. Common bus interfaces like I2C and SPI require hundreds of Khz to many Mhz. Since you want to see these digital signals, you want a bandwidth supporting the rise time so the actual requirement can be much higher than the fundamental frequency. Not to mention power converters, filters, adc/dac, etc. Which can typically be a common project design debugging case where the extra bandwidth ensures you're debugging the circuit rather than being led astray by the limits of your tools.

[@sarowie]

@@epeglab1o1 then you need a digital probe/Bus decoder/Buspirate etc. Sampeling the signal analog when you know that you problem is in the digital domain is... not necessary? The, the time correlation of the analog signal with the digital is awesome with a probe scope, but I can trade that in for having a specialized probing of the digital signals.

[@epeglab1o1]

@sarowie well it's not always about the actual data being sent that needs to be decoded. It's also about seeing termination behavior, how sharp rise times and fall times are, and also debugging issues like xtalk etc. I see your point and if I was only working in embedded then you would be correct, but in hardware design you can't get away with just using a saleae

[@easyBob100]

I ❤my 2 channel Siglent. :)

[@tomschmidt381]

Retired EE here, for the hobby stuff I do now 2-channels w/logic analyzer is all I need. Even when I was working back in the prehistoric times with the TEK 2445 I'm trying hard to remember if I ever needing more then 2-channels.

[@marklewus5468]

hey Dave, great video. I think the price delta between 2 and 4 channels has changed substantially over the last few years. In 2019 I bought a Siglent 2202X 200 mhz (2G samples/sec) DSO with logic analyzer, serial decoder, etc. it cost $1800. The four channel was 40% more. i’ve also noticed new low end scopes double the channel count but memory and sample rate don’t change so you end up with lower performance.

[@ray73864]

The only purpose I would have for an oscilloscope is for testing retro consoles, don't need more than 2 channels for those, and it would spend most of its life just on the shelf. One day I will buy one, but I've yet to really work out what a decent one would be, since it has to be under like $500, and must be purchaseable here in Australia in AUD.

[@SimonBauer7]

usb scope, an owon vds 1022i is enough, costs 100$ US

[@Chris-Brown-]

dont use more than 2 channels that often, but when I do its very handy, totally worth it

[@rusle]

This reminds me from when I was studying for my bachelor degree in electronic. I had already had a electronic background and knew how to use an oscilloscope but I preferred to use a simple analog oscilloscope when I was doing mandatory lab work. I found it much faster to work with because I had no struggle to get correct settings.

[@mikecassap]

Dave we were born with only 2 hands 1 probe for each hand 😂😂😂

[@randynovick7972]

I laughed.

[@EEVblog]

Fingers.

[@gorak9000]

You know the probes come with those little springy clips, so you don't have to hold them...

[@jaro6985]

@@gorak9000 I threw all that junk out, why would you need those. Scope probes are like DMM leads, pointy.

[@kwpctek9190]

Nice to hear Dave chat over his industry past. Seldom he goes into that kind of detail since his industry passion is seeing where companies are "pushing the proverbial envelope". I think he's that kind of guy where at the end of each day, he can't sleep unless he's absorbed something new (or at least climbed his roof to dust off a panel or watched Scott Manley).

[@3beltwesty]

In the mid 1980s when using a consulting firms Hitachi "phosphor type" analog storage scope sometimes the trigger circuit would not grab a pesky waveform right at the glitch/problem area. So we used a 465 Tek as the trigger and uses its external output to trigger the Hitachi storage scope. That Hitachi analog storage scope was old 5 to 10 years old in 1985 and might have been bought in Japan since that was our clients O scope. The display was dim as can be and you turned off the room light and farted around to get the trace photographed with the Tek Polaroid camera.

[@markburton3306]

Way back in ancient history I worked as an engineer in TV studios. For our maintenance rooms we had quite expensive 4 channel scopes. However, in the vision bays we’d have vector/waveform scopes and usually a general scope which was usually on 2 channel. When live tv went off air we needed to diagnose problems very quickly and we wouldn’t want to have to mess about with complex scopes.

[@TheKnobCalledTone.]

Not everyone is an electronics engineer with money to burn, Dave. For many casual users - especially those on a limited budget - a 2CH is perfectly fine.

[@EEVblog]

And I said as much. But 4CH is the new entry level standard in budget scopes.

[@py2bnd-sota411]

​@@EEVblogIf You look for budget bandwidth instead of channel number you are probably going for a 2 Chanel Rigol DS1202Z-E which has no 4 Chanel version in this line on 200Mhz bandwidth. From the practical standpoint I don't remember that I ever needed 4 channels, but frequently faced bandwidth and sample rate limitations. Over the time I learned that it's better to invest in bandwidth, sample rate and good probing instead of chanel number - That's why I chose the 2 Chanel 200Mhz DS1202Z-E instead of channel numbers that are even more degraded by sample rate interleave.

[@ppdan]

All recent bench scopes I have seen in labs are 4 ch. The only 2ch scopes I have seen there are 10-15 years or older. Haven't seen lots of rackmount scopes yet but I think this is the future. Lots of manufacturers use windows for their scopes and if some bug, update, hack or whatever breaks or heavily slows down the system it can be their responsability to fix it, something they don't have to care about with a rackmount scope since the computer will be the user's responsability. The user will also be able to choose the screen size he wants and the user interface can be updated or customized.

[@TrickyNekro]

I'd say primary drive for the 2 channel is either education or particular government contracts. Racks usually get a rack unit. That would be my guess.

[@MKSense1]

The LCR meter project you worked on was a nice one .

[@packapunchburger]

From what I've heard in the past from manufacturers , a good chunk of oscilloscopes and the like will be purchased to be mounted straight into bespoke rack mounted , automatic test rigs for verifying and QA of boards off the production line without much operator interaction, set and forget . Unfortunately, I can't remember what figure it was

[@asid61]

I had a 1-channel $30 1Mhz pocket scope throughout high school, and got a 2 channel Owon USB scope in college for $100. Both served me well. But if I had to go back in time, I would never buy the 2 channel scope. I would have skipped a couple of restaurant meals and just gotten their 4 channel version. 4 channels is dramatically more useful if only because you can debug SPI far easier. SPI was a bear to probe with my old single channel. Bandwidth matters a lot less; above 50MHz is leaving the realm of a hobbyist IMO. For most stuff even 10MHz is enough. I can see thr application for 2 channels, but if youre really that broke just get the 1 channel and upgrade to a 4 later.

[@ellindsey000]

Ooh, I remember using Rabbit processors! I was in a job where they needed to tunnel multiple serial ports over ip simultaneously, along with contact input and output with real time monitoring of everything. I did eventually convince them to switch to a STM32 solution instead when the Rabbit's hard 1 Megabyte memory limit got to be too much of a problem.

[@gregfeneis609]

There's also the price anchoring effect. The 2ch already has a great profit margin, but it can serve as an anchor to make the 4ch price seem more reasonable, and its margin is even better than the 2ch

[@egonotto4172]

17:44 This are 8 400 W and one 200 W electronic loads

[@EEVblog]

D'oh, yes of course.

[@evensgrey]

Getting a higher-end 'scope than you need for the current project may end up saving money later when you have a new project that does need it, and you've already got the thing.

[@markosavic1695]

Building portable test racks is fun! Could you make a video on how to make a rack with PCIe and the Eurocard standard?

[@wtmayhew]

I taught digital electronics, and it was usually easier to get students to use four analog probes on an MSO scope for simple labs. The learning curve for breaking out the logic pods and setting up the digital section of the MSO was pretty time consuming for students. I always had at least one lab where using the digital side of the MSO was required, such as tracking glitches in a ripple counter, but in that lab I had to be sure to leave enough time for the students to learn the test equipment.

[@thomasmaughan4798]

For the past 40 years I have had excellent use of analog 2 channel oscilloscope. Occasionally I could use a 4 channel scope but I don't really need one and very expensive. Exploring transformers is one such use; voltage and current going into the primary plus voltage (and maybe current) on the secondary. Another use is 3 phase power systems such as the control module for brushless motors. But I can still monitor that sort of thing using external trigger one one of the phases and the scope for the other two phases.

[@pp3v42_g3h]

17:42 those are dc loads for the different rails of a modern ATX PSU including the rare multi 12V rail ones too.

[@ericksonengineering7011]

I always used a simple guideline: Engineer or scientist: 4 channel scope. Test Technician or production technician: 2 channel scope. It worked back in the analog scope days, and is still valid. In general, production techs don't have time or need to mess with 4 channels. Of course there are exceptions. Remember Tek 465 and others have 'trigger view', a 'free' third channel. Dave

[@larryh8072]

Hey Dave. Why not a single channel. I spent 25 years as a test engineer designing test stations to test audio amplifiers for hearing aids as well as the finished product. We ordered tons of cheap, single channel scopes to monitor the audio o/p of the system. Actually not so cheap back then. A 20 MHz single channel Hammeg scope still ran $500 Canadian dollars in the mid 1980’s.

[@MonguzTea]

I started with a soviet made single beam 2 inch crt scope. Modern cheap 2ch digital scopes are still mindblowing for me. $250 gets you equipment that would cost $20,000 20 years ago. For consumer electronics repair they are more than enough.

[@grumble2009]

As a former Z-World employee, it's cool to see that R2000 core module :) I'm happy that Dynamic C did what you needed. For me, coming from K&R and Ansi, I found it to be a minefield. But then again, I wasn't the target customer for it.

[@8thsam]

I’m a photonics test engineer and we could use a one channel scope at work and notice. At home I have a 2channel siglent as well as a 4 channel tekronics because I didn’t need 8 channels but I did need 2 scopes often enough to grab a budget model.

[@TYGAMatt]

As a hobbyist I'd have to say get a 4ch if you can afford it. I started with a 1ch and it served me well for very basic stuff. Then got a 2ch and saw the benefit and quickly went 4ch. I still grab the handheld 2ch quite often as it's super handy. We have one thing that my staff have to check and they only need to know two signals so the 2ch handheld scope works perfectly.

[@falxonPSN]

How do mixed signal scopes factor in? Several years ago i bought a Rigol 2 channel analog + 16 channel digital scope. That is super handy for a lot of microcontroller work.

[@EEVblog]

If that's all you need, then great.

[@kensmith5694]

Something you didn't mention is that if you are buying a lot of scopes saving a few bucks on each can be important. Some year back while designing a product, I had no less than 4 scopes connected to it at the same time. They were all at different time scales and displaying what was going on in different sections. I had waveforms at many different frequencies that were evolving over time. Some were at a few hundred Hz. Some were at about 10Hz Some was at about 150KHz and another one was in the MHz. They were mostly old 2 channel scopes.

[@MadawaskaObservatory]

6 channels would be nice.

[@keggerous]

I'm a beginner and I've already come up against multiple situations where I needed more than 2 channels. I ended up working through everything without an oscilloscope but, after thinking about it for a while, an oscilloscope would have revealed the issue almost immediately and a 4-channel scope would have made the entire issue much simpler. So, in my opinion, the oscilloscope I'm buying will be 4 channel. I'm doing pretty simply logic stuff and signal amplification, and I can see massive benefits for 4 channels. I can't imagine the benefits to people who are doing more advanced work than myself.

[@TrueAudioTest-up7rp]

4 channel scopes don't have many uses cases for hobbyists, people mention SPI analysis, but SPI has just 2 data lines, so 2 channel scopes are just fine.

[@RealLimerickman]

Once I used 4 channels oscilloscope. I hated the two channels scopes. 4 channels saved me alot of time to debug and to record AC/DC/Digital signals side by side.

[@julesl6910]

I work on amplifiers, repairs and modifications mostly. I can get the job done with a 2 channel as I have a separate signal generator.

[@annieworroll4373]

Definitely good to go 4 channel, though I was working with a hard budget limit of 200USD so I got a two channel portable hantek as my only scope. I like it, though the UI could be better especially for an oscilloscope newbie. And given its size, if I ever need it for my car where scopes are occasionally useful, it's going to be quite useful to have a device that small.

[@martinmckee5333]

I did use the Rabbit 2000, for a couple of projects. None for myself though. Those were projects for one of my professors.

[@uni-byte]

I think need a 68 channel oscilloscope for my next Arduino project!

[@gorak9000]

That's called a logic analyzer. Even crazy expensive scopes only go to 6 or 8 channels

[@darrenconway8117]

I have 2 plus 2 channel oscilloscopes. That is 2x two channel 100MHz scopes. Never used all 4 channels simultaneously. I don't want higher bandwidth because if you look at the passive probe performance, they limit the usable bandwidth of the scope. High BW scopes need active probes, and they often cost more than the scope, especially 4x channels.

[@spehropefhany]

I just bought a 2-channel scope for about the price of a single 500MHz probe just to throw in the luggage, along with a logic analyzer for 8 channels. A 2-channel 1Gs/s 100MHz scope is better than nothing, and if it gets stolen or smashed it's not a big deal. I have better stuff on the bench, but if I don't have it, it's not much use.

[@scotshabalam2432]

Might I suggest a air filter that creates positive air flow through the equipment and out of the rack to prevent dust? I'm doing a setup like this just to hold my vintage game consoles so they never get dust in them.

[@LawpickingLocksmith]

Siglent is so far the ONLY one that can see the light and let you place your monitor onto their rack unit. A chance for Rigol to clean up the ed market?

[@volodymyrzakolodyazhny]

Being more and more experienced DIYer I see that the more experience I have the less channels I need. Last 10-15 years I use the only one channel.

[@gorak9000]

I find it's quite the opposite - lots of times it would be handy to have 6 to 10 channels. And for some applications, much much more. I have a couple decent 2 channel scopes, but within the last couple of years, ran into multiple instances when having more channels would've been useful. I managed to snag a busted Keysight 2000 series with 4 channels and fixed it. For more channels than that, I have an older Agilent Logic analyzer I fixed up - 384 channels, and I've used it for some reverse engineering that would've been nearly impossible to do without at least 70-ish channels.

[@oliverthane2868]

Another good reason to use something off the self is failure ... Definitely not a fun time stuck in a factory in Asia when both the test rig and back up unit failed ... It was going to take weeks to get a new one shipped ... In the end I replaced it with a scpi power supply I bought in the afternoon, changed the code that evening and was back up and running the next day ... Much better

[@DimasFajar-ns4vb]

your skills is amazing good job sir

[@NullStaticVoid]

I've never used more than 2 channels on my 4 channel scope. I'd prefer if it had better resolving power on it's two channels I use. I mostly only use it to test audio gear, so I can see a waveform and the difference after passing through the device under test.

[@IvoTrausch]

We still buy the TBS1000C scopes at our company because it fits the racks they made in the early 2000s (for whatever scope looked like that then). We could modernize the racks but incidentally the bloke that made the racks also retired in the early 2000s. We're also one of the largest automotive suppliers in the world. ¯\_(ツ)_/¯

[@mikefinn2101]

Very informative many thanks really enjoyed this video

[@originalmianos]

Home use, I have a 16 channel logic analyser, not worth one more cent to get 4 channels. I have the DHO802.

[@JohnnieBravo1]

Yeah, I effed up and bought a 2-channel scope. But all I was doing was analyzing (initially) CANBuss data. But it was affordable for infrequent use. I haven't actually "needed" a 4-channel, bbut as I have a tool fetish, I may have to get one. So, between the two, I'll effectively have a 6-channel scope(s).

[@handyman7147]

I will wait for the 16 channel oscilloscope before I ditch my 2 channel.

[@davadoff]

Sometimes manufacturers will even sell a MORE expensive version that’s inferior. If there’s a market for it then they’ll make it. I bought such a product once (I was uninformed).

[@rohitkhanna4487]

Hi Dave, I would like to correct you as I work in a university from last 10 years, most university in western world buy 4 channel scopes, the only button students know to use on a oscilloscope are autoset, time base knob and volatge amplitude knob.....most universities spend tons of money buying good scopes more than 3/4ths of students have no clue why they are studying engineering as they want to work for a bank......

[@briantamburelli7573]

I have a low cost lab (under $1300.00). I bought the Hantek DSO5102P 2 Channel 100Mhz and I'm very pleased with it.😁 This Oscilloscope set me back $259.00+tax. I like the accuracy and have had no issues with it.😁

[@jameshackett9992]

Also another thing procurement RFQ docs would of been set in stone for 2 channels since the 90s in gov and no one wants to open that can of worms, getting that rewritten, it cost more on the rewrite than the procument

[@SupportToolsBlog]

I wonder if setting up eBay searches for the rack mount scopes might be a way to find a good deal

[@MrPaulMorris]

I didn't realise how out of touch I've got since leaving my bench work behind. Last time I worked in (and managed) a radio repair workshop four channel scopes weren't even a thing! Nothing we did needed more than two channels and it was rare even to use more than a single channel. 25 years in electronics maintenance: avionics (RAF still working on valve kit in the 80s-90s!), national radio data/voice trunked PMR system, mobile telephony and radio data systems supplier and integrator before heading out of the field to work as a network planner (mistake, should have stuck to hands-on work in the field and workshop). 20-odd years since leaving the industry but still have a 2 channel scope which more than meets my needs. Also a radio amateur although my licence has long ago lapsed through a combination of lack of space/time and getting married... (G7GIN as was...).

[@MrMaxeemum]

For a home lab oscilloscope, 1 channel is a must and a 2 channel is a luxury. In a work environment, why not spend the extra on a 4 channel, as you are more likely to need them at some point. In a home lab, I don't mind struggling once in a while with 2 channels. I do want to know more about that weird ass boat, never seen a boat like that before.

[@TekCroach]

Definitely he is a businessman, so no point in blaming him. For the DIYers, you can find thousands of channels to suit the most.

[@craign8ca]

I bought two 2 channel analog osciloscopes for 20 USD. I also bought a low-end 2 channel Owon osciloscope for 100 USD at a ham radio swap meet. For the work that I do, which is mostly audio stuff, these are more than enough.

[@ancientlink0]

Where did you get it for 20 usd?

[@addictedtofigbiscuits]

@@ancientlink0 aliexpress is full of these cheap scopes, but the very cheapest are VERY low spec.

[@craign8ca]

@@ancientlink0 At an auction. A repair shop closed down. I was also able to get a nice VOM too.

[@ancientlink0]

@@craign8ca thanks, was tge auction online?

[@Gengh13]

For the cost of that R&S mounting rack you could buy a cheaper scope and a 3D printer and print a mount for your scope.

[@py2bnd-sota411]

No, if You go for the Rigol DS1202Z-E 200Mhz oscilloscope it has 2 Chanel and no 4 channel option available on this line on 200Mhz. And for me the 200Mhz bandwidth was more important than 4 Chanel. By the way, I don't remember that I ever run out of chanel's. The 2 channels were always enough.

[@3beltwesty]

In Dynamic signal analyzers like the HP 35670a i have both the 2 and 4 channel versions and sometimes use the 3rd or 4th channel.. but mostly not .

[@sarahjrandomnumbers]

24:42 Looks like the front part of the boat from Clarke and Dawe - The Front Fell Off 🤣🤣

[@jessicav2031]

Market. Segmentation. MBAs ruin everything. Also, the number of buttbot comments is insane.

[@jeanmichel9207]

Just reported them if everyone do like that we will be safe from spam and scammers .