Beginner Oscilloscope Best Approach to Purchase Now or Later? - Page 1
Forum section: electronics / beginners

author: Lowkus
author_rank: Regular Contributor
timestamp: May 15, 2021, 08:13:44 pm
content: I am a beginner without an oscilloscope, and I know I need to get an oscilloscope eventually but for the next six to eight months I won't have time to practice electronics. Should I wait to buy an oscilloscope until months later, figuring prices and options will be better by then? Or should I expect prices will be the same, so just buy one right away in case I get an impulse to muck about with it some evening?My current plan is to get one of these scopes, but is there a better option I should be looking at? I want four channels minimum, but beyond that I don't have a lot of experience to know what I'm going to need. Most of the projects I'm thinking about will involve either audio processing or robotics.-Siglent SDS2104X Plus-Siglent SDS1204X-E-Something else?

author: Robert Smith Eco Warrior
author_rank: Regular Contributor
timestamp: May 15, 2021, 08:48:33 pm
content: I have just got my first oscilloscope. My budget was limited ( about £50) and I don't need to go for anything too fancy. I got a Hameg 303-6 and am very pleased with it.I just googled Siglent SDS2104X Plus and it looks like your budget is far bigger than mine

author: wizard69
author_rank: Super Contributor
timestamp: May 15, 2021, 09:46:41 pm
content: When you say "robotics" that covers a massive area. Depending upon what you mean a scope with isolated inputs might be advised. If you are starting out though I'm hoping you don't jump into high voltage and complicated systems, so maybe not a concern.As for being a beginner you don't need a scope to start with but it quickly can become a very useful tool in the learning process. In some cases you might learn more with a device like "Analog Discovery", for an initial low cost investment. Well it was low cost at one time. In any event 8 months is a long time, what is available on the market could change and frankly you will have more knowledge about what fits your needs best. So I would suggest holding off.On the flip side we are likely to go into an era of extremely high inflation in the USA. This due to the idiots in Washington, for the guy trying to make a living it is going to suck. So one could argue that investing know will save you money.Quote from: Lowkus on May 15, 2021, 08:13:44 pmI would not have an expectations at all. I've been looking at a number of products for various projects I have around the house and the price increases are staggering in the last few months. Literally everything has gone up in price significantly. Will it cool off in 8 months who knows. I just don't want to say one way or the other, long term, but right now I'm a bit shocked.QuoteThat right there is the best reason to hold off. Buying a scope is a big investment and frankly you want to buy something that is a good fit. It isn't like buying a DMM where no matter what you buy you will find yourself wanting / needing another. Don't even start to shop until you have an idea about what you need and why.QuoteThere are a lot of scopes on the market and frankly a lot of used ones. I'd hold off and when you have a better idea of the what and whys, I'd canvass the market then.Siglent isn't the only brand name, though they do have a good rep for a Chinese scope.

author: wizard69
author_rank: Super Contributor
timestamp: May 15, 2021, 09:48:56 pm
content: Quote from: Robert Smith Eco Warrior on May 15, 2021, 08:48:33 pmThis is actually a smart move. From my perspective there is no reason to waste money on a new highish end scope when you can learn perfectly well with a used scope.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 16, 2021, 06:03:46 am
content: Oh man, the inflation issue is one I wasn't thinking about for the oscilloscope market, but that totally makes sense. I've had my money sitting in a savings account for ten years, expecting a catastrophic market collapse so I didn't want my money in the market. I had no idea the Fed was going to throw the working class under the bus so they could save the stock market gamblers. Capitalism for the poor, socialism for the rich.I think I'll buy the 2104x Plus now to hedge against price rises in the future; at best I doubt the scope will drop in price by next year, and the newer scopes will be much more expensive to sneak in their adjustment for the inflation. I know the scope I'm looking at is more than what a beginner would normally start with but I've been programming computers for 30 years, gotta give myself a gift every now and then to offset the pain of wrecking my body at a computer for so long.

author: Old Printer
author_rank: Frequent Contributor
timestamp: May 16, 2021, 02:47:20 pm
content: A couple years ago I bought a Siglent 1104x-e as my first digital bench scope. I had a couple old Tek analogs and an Analog Discovery (which I love and still use regularly). At the time I felt the 1104 was the best bang for the buck, and it still may be. I am a hobbyist and it is likely way more scope than I will ever need, but... I like my toys and would love to have the larger touch screen of the 1204. At another $900 that’s an expensive luxury. Except for a bit more horsepower I am not sure what else the 1204 would give me and likely nothing I will ever use. The only thing I would add is as long as spending the extra $900 won’t prevent you from buying other gear, like a good DMM, a decent function generator and some good power supplies, a good solder station, etc. etc., then go ahead. Those other pieces of gear, and then some, will be required for you to get good use of your spiffy scope, or any scope for that matter.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 16, 2021, 04:18:48 pm
content: I've been saving money to buy a house, I'll dip into that fund to buy the extra test gear. It's not like I'm going to buy a home anytime soon anyway, home prices are inflated so much now.

author: bdunham7
author_rank: Super Contributor
timestamp: May 16, 2021, 04:36:39 pm
content: The 2104X+ is a lot of scope for the money after hacking, so I certainly won't discourage you from getting one, but depending on your budget, you might be better served by getting the 1104X-E and an SDG2042X sig-gen, and of course hacking both of them. OTOH, the 2104X+ looks pretty good and I'm considering the upgrade myself. Either way, having them on hand will probably lead to you taking them out and using them and learning stuff in the process.I've no idea whether inflation is going to be a bigger factor then competition--the low/mid scope market is extremely competitive--but I doubt the prices will be dropping anytime soon so it's safe to buy now. There's a discount at TEquipment for EEVblog members.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 16, 2021, 05:39:40 pm
content: Is there a thread I should visit to get the discount code, or should I ask Sales@TEquipment.NET?

author: rstofer
author_rank: Super Contributor
timestamp: May 16, 2021, 07:04:06 pm
content: Reply 1534 here:www.eevblog.com/forum/testgear/eevblog-members-discount-at-tequipment/msg3502502/#msg3502502

author: ledtester
author_rank: Super Contributor
timestamp: May 16, 2021, 07:05:42 pm
content: QuoteFor audio circuits you don't need a very high bandwidth scope, and robotics is primarily digital these days.Since you have the budget I'd have a good look at the Analog Discovery 2. At only $400 it packs a lot of PC-controlled lab instruments into a compact form factor:- dual channel 30 MHz oscilloscope- dual channel arbitrary analog waveform generator- bipolar programmable power supplies- GPIO pins- digital pattern generator (16 channels)- logical analyzer (16 channels)The WaveForms program gives you access to all of these capabilities, but you can also write your own programs (like in Python or C) to implement your own applications.The integrated bipolar power supplies, waveform generators and scope, for instance, is perfect for testing op-amp circuits.The AD2 reference manual:https://reference.digilentinc.com/_media/reference/instrumentation/analog-discovery-2/ad2_rm.pdf

author: Calaverasgrande
author_rank: Contributor
timestamp: May 16, 2021, 09:44:09 pm
content: Picked up a Rigol DS1054Z last year and it's been nothing but wonderful.It's really helped to increase my comprehension for some topics that were gray areas for me.4 channels, decent ergonomics and pretty good menus system.It is however a 4 or 5 years old design now. So there are probably newer models which beat it.That said it has to be one of the most written about scopes on EEVblog.That's the reason I went with it myself over several other scopes with similar features and price.

author: tautech
author_rank: Super Contributor
timestamp: May 16, 2021, 11:56:00 pm
content: Quote from: Lowkus on May 16, 2021, 05:39:40 pmOr you can also get 6% from Saelig:https://www.eevblog.com/forum/testgear/equipment-discounts-from-saelig/

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 17, 2021, 03:11:06 pm
content: 1. (Almost) Any functioning oscilloscope is better than no oscilloscope at all.2. A single channel scope is almost useless unless you have a particular special purpose application. For example I use my antique Tek RM503 to frighten children and, in x-y mode, to display a ScopeClock face or make Lissajous figures.3. Two channels good, three channels better, four channels best. But does every channel need its own set of controls? That third or fourth channel might not get used very much, so why do you need its control knobs always present, taking up panel space? But when you need the fourth channel... you need it, so using a shared set of controls is tolerable.4. Unless you do heavy digital data decoding or VHF RF work you probably do not "actually" need a fancy (read expensive) scope with high bandwidth or hardware data decoding features.Once I got a good unit of the Rigol DS1054Z and now that the software bugs are shaken out, I still find it completely adequate for my hobby and pseudopro use cases. For example right now (and continuously for the past 3 or 4 days) I am using it, all 4 channels, in roll mode, to monitor the control voltages of a new modular synthesizer that I am putting together, in an effort to try to understand where all the racket is coming from and going to. I like this effect so much that the Rigol just may become a permanent part of the music synthesizer rig.The Point: You may be able to save a bunch of money by buying a used scope that actually meets your present and some future needs, rather than breaking the bank by buying a new and feature-packed scope that never gets its capabilities stretched.Just my 4.5 cents worth.

author: rstofer
author_rank: Super Contributor
timestamp: May 17, 2021, 06:22:05 pm
content: Quote from: ledtester on May 16, 2021, 07:05:42 pmProbably the most important tool on my bench. I love this thing! It replaces an entire bench worth of equipment and I can carry it in a backpack along with a laptop.Here's a cool use case: You're doing some kind of input/output on a Raspberry Pi running Python or C++ code. You run the Waveforms software on the same Pi and you can use the Pi to diagnose itself. Somehow, this seems cool - maybe it's just me.I don't like the new and improved price ($399) compared to the old price ($279) but I already have one so it doesn't really matter. It's those university kids - buying up all the AD2s for their at-home lab work. At long last, the AD2 is back in stock but it has been sold out since Covid first appeared.For somebody wanting to actually learn electronics, I would absolutely recommend the AD2 over a bench full of gear. I can spend an entire day playing with a 10k resistor and a 0.1 ufd capacitor looking at a low pass filter in both the frequency and time domain. Throw in a 27" monitor and a Color LaserJet and things look pretty good.Oh, and let me know when your scope can do a Bode' Plot as nice as the attached.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 17, 2021, 09:17:42 pm
content: I don't think I'd replace a full oscilloscope with a PC scope, but is the AD2 adequate as a replacement for a dedicated function gen? Has Dave done a video on the AD2 and if so was the video recent enough to give a proper impression of the AD2 as it currently exists? If they've raised the price to $400 I'm assuming there must be some increased reliability or functionality in the product to justify the price rise, or is it higher because of parts scarcity, or maybe an early victim to the inflation creep that's coming?

author: SmallCog
author_rank: Frequent Contributor
timestamp: May 18, 2021, 02:22:08 am
content: It always surprises me how many people are new to the hobby and looking to spend a small fortune on lab gear.If you don't need a scope today, wait and keep an eye on ebay/facebook marketplace/ or whatever your local classified website is. You'll probably bag a scope for not much money.If you find you need something better you can flip it for what you paid for it. If you find you don't use it you're not out by much! If you blow it up doing something silly you're also not out by much.If you've got an itch you need to scratch buy one of those scope kits on ebay, use it to practice your soldering and stick it in your toolbag if you need to do some repairs out of the lab. They're not great, but they're still good for looking at pulse timing or audio stuff. A battery powered scope can be handy for other stuff too...

author: AtomicRob
author_rank: Contributor
timestamp: May 18, 2021, 02:41:48 am
content: Some years ago as a first scope I bought an old Tek 475 in perfect working shape for about $100. I figured it was a scope with all the typical controls and good for learning the basics of operation. Turns out I’ve never needed to upgrade. Caveat is that I’m only doing analog circuits, audio/music stuff, so my needs are very limited. But I can still recommend starting with a simple, basic scope and planning to outgrow it later if you need to. The actual scope you have on your bench is always more useful than the theoretical scope you might get in several monthsand if you buy used you can usually resell later for about the same amount.

author: rstofer
author_rank: Super Contributor
timestamp: May 18, 2021, 07:02:01 pm
content: Quote from: Lowkus on May 17, 2021, 09:17:42 pmYes, the AD2 has 2 channels of 14 bit 100 MS/s 30 MHz arbitrary waveform generators. There are quite a few built-in waveforms and the two channels can be combined to form a sweep generator.You can download the Waveforms software and play around with the Demo device. There's a lot of capability in waveform generation.QuoteDave did a video on the original AD but AFAIK the only major change is with the power supply outputs and this involves the capability of increasing the current by feeding the AD2 from a wall wart.I'm not aware of a video detailing the AD2 but there are MANY on the Internet.QuoteI have attributed it to opportunistic pricing. With Covid, universities couldn't have in-person lab classes so there was massive demand for labs-at-home and you couldn't get an AD2 even if you wanted one. That situation has eased and there are a couple of thousand in stock at Digilent.Other items haven't increased in price so I am definitely leaning toward opportunistic pricing. And, when NI took over Digilent, they had competing products. It wouldn't do for the Digilent products to supplant the NI products.I have the original AD and the AD2 (plus the Digital Discovery) and I like them a lot. I spend some time going over fundamentals and there is nothing on the market that does a better job than the AD2. I have the new Transistor Curve Tracer attachment along with the Impedance attachment (plus the BNC adapter, of course) and these optional gadgets do a very nice job.The curve tracer output is for a 2N4401 transistor and IIRC, the impedance plot is of a 0.1 ufd ceramic capacitor.The Breadboard Breakout and Breadboard Adapter are pretty handy gadgets. It doesn't show it but the Breadboard Adapter comes with a matching Breadboard. Very handy for small learning projects.https://store.digilentinc.com/test-and-measurement-equipment/adapters-and-canvases/When the AD2 was just $279, I had no problem recommending it in every oscilloscope thread. Today, I'm a little more subdued. $399 for a $279 gadget is ridiculous.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 18, 2021, 07:13:09 pm
content: I like the idea of the AD2, and if I could afford one I'd probably buy one. But... you need a laptop or other PC to operate it, yes? So I see it more as an accessory _in addition to_ an actual bench digital oscilloscope. After all, one can always download the data from a digital scope to a PC and calculate Bode plots and such, can't one? (I really don't know; I do know you can do FFT on downloaded data so I am assuming the rest is possible too.)

author: rstofer
author_rank: Super Contributor
timestamp: May 18, 2021, 08:10:43 pm
content: In my world, everything is digital. I don't really do much with analog and never have.So, I will always have a computer on my desk or in a backpack. Or, the ultimate case, running Waveforms on the Raspberry Pi I am writing code for. Dual monitors would be helpful here...I do like analog computing and I do mess around with that. There will always need to be some scheme for displaying the outputs. Typically, this was done with a chart plotter because things don't happen all that fast on an analog computer. A scope with decent X-Y capability is workable as long as it has single shot mode and some method for downloading the image. An AD2 with a 27" monitor and a Color Laserjet is even better. It isn't always necessary to have X-Y but every scope I have ever seen has this capability. Actually, single shot mode isn't always required. It's just easier...It's pretty easy to use something like MATLAB or Octave to read a file of voltage samples and produce an FFT.Attached is an FFT project that runs in both MATLAB and Octave. Octave is a free MATLAB work-alike.

author: james_s
author_rank: Super Contributor
timestamp: May 18, 2021, 09:02:13 pm
content: Quote from: Lowkus on May 16, 2021, 04:18:48 pmCareful with that. A house is an investment, an oscilloscope is a depreciating asset, especially if you are not using it to earn a living. When I bought my house it was a very tight squeeze and I made a lot of sacrifices, it completely cleaned me out at the time and it seemed like a crazy amount of money to spend. In retrospect it was the smartest thing I ever did and even during the big housing crash of 2008 the value never dippped down to what I paid for it. At the time a lot of people told me I was crazy since renting was so much cheaper but today I'm watching those people struggle as their rent is more than my mortgage which is just a few years from being paid off. Housing does tend to have bubbles, but over the long term it has always gone up.As far as oscilloscopes, my advice would be wait until you need one. I don't think entry level scopes are going to get hard to find and if serious inflation does happen you'll probably have more important things to do than play with your hobbies.

author: james_s
author_rank: Super Contributor
timestamp: May 18, 2021, 09:04:54 pm
content: Quote from: alsetalokin4017 on May 18, 2021, 07:13:09 pmYou do need some kind of PC, but who doesn't have a computer these days? What are you using to interact on this forum? It doesn't need to be a high end laptop, a cast-off freebie or inexpensive ebay find would do the job.

author: ledtester
author_rank: Super Contributor
timestamp: May 19, 2021, 03:06:11 am
content: Quote from: alsetalokin4017 on May 18, 2021, 07:13:09 pmFor a hobbyist's first scope I think the 30 MHz bandwidth is perfectly adequate. Seeing tear downs of and hearing the professionals talk about the latest and greatest pieces of test equipment is interesting and educational, but I think it leaves the impression in beginners that you need that kind of high-performance equipment to do anything. Perhaps more videos showing what you can accomplish with lower-end equipment would be a good idea.QuoteBeing able to easily coordinate the activities of the waveform generator, power supplies, scope, digital I/O's, etc. is the main benefit here. A Bode plot will require configuring your function gen and taking a scope capture several times -- something you'll want to automate.

author: james_s
author_rank: Super Contributor
timestamp: May 19, 2021, 06:29:30 am
content: Quote from: ledtester on May 19, 2021, 03:06:11 amBack in the day, people managed to design and debug all sorts of cool stuff with a 15MHz analog CRO. When I was a teenager I would have traded my soul for something like the Chinese 100MHz DSOs you can get today for a few hundred bucks. At that time 100MHz bandwidth would have been extravagant. Sometimes there is no substitute for bandwidth, but the average hobbyist doesn't truly need anything fancy most of the time. You can learn just as much working with lower frequencies.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 20, 2021, 03:49:58 am
content: Quote from: james_s on May 18, 2021, 09:02:13 pmI bought a small house toward the end of 1999 (or maybe it was 2000... my memory sucks these days), a couple years later I damaged my tendons from working too much and was forced to sell everything at a loss. I would have made nearly a million USD if I'd kept that house, so I'm very cognizant of how profitable it can be to own a house. The problem with housing around Puget Sound nowadays is that we've had an insanely huge influx of wealthy tech workers coming to the area for the last two decades, with more coming every year. The housing demand is crazy and the low interest rates have only pushed home prices higher. A single-income worker like myself can't afford the kind of house I want to live in. I've also gotten tired of the darkness, crowded roads, unfriendly people, homeless masses, and increasing crime that's been growing in this region. I'm hoping in the next few years to find a new area to live where the quality of life is better and more affordable, and I'm also trying to start my own business so I can stop being dependent on an employer who provides what is effectively an unreliable and dwindling income source. The electronics projects I'm planning will be for commercial products for my business. The oscilloscope will be a depreciating asset but I don't mind that, so long as it gets me closer to escaping the day job.

author: james_s
author_rank: Super Contributor
timestamp: May 20, 2021, 07:32:42 am
content: Quote from: Lowkus on May 20, 2021, 03:49:58 amOuch. Yeah it sounds like you're in the same area I am, and I've observed the same thing. Thankfully the particular suburb where I am is still very low crime and I haven't seen any homeless people around here at all but Seattle proper is kind of a dump these days unfortunately. I'm all the more glad I bought when I did because there's no way I could afford to live where I do now if I hadn't. My house has become absurdly valuable which sounds great until you realize that my property taxes are correspondingly absurd and it's wealth only on paper, if I sold it I'd have to buy another one somewhere else. I'm one of those tech workers, but I grew up here rather than transplant. People started fleeing California after they screwed that state up in the 80s and the flood never stopped. I like the area because it's home but I really don't understand the draw that keeps people pouring in from everywhere else. I'd be far happier if about 50% of the population moved elsewhere, I much preferred the quiet rural areas with grassy hills, farms and orchards. Oh well.

author: manuel42
author_rank: Contributor
timestamp: May 20, 2021, 08:34:38 am
content: I just started out with electronics and don't have much experience.Out of curiosity i've bought a cheap Rigol DS1002 Z-EI'm sure i can do everything i need with this oscilloscope but i've already replaced it with a (much more expensive) Keysight DSOX1202G.My subjective reasons were:I found the rigol to be rather slow/unresponsiveWhen changeing resolution, it often lost focus an i had to fiddle around to get the information back onto the screenI wanted a function generatorKeysight did a good job with their adds and i like their brandAgain, nothing crucial, but i do like it way better now.

author: wizard69
author_rank: Super Contributor
timestamp: May 20, 2021, 08:36:24 am
content: Building a house right now is going to be a shock to the system. lumber is 3X or more the cost it was a year ago. I've been working on a few projects around the house, as money and time permit and was totally dismayed at the cost of a 2x4 and a sheet of OSB. Absolutely disgusting!!!!!!Quote from: Lowkus on May 16, 2021, 04:18:48 pm

author: wizard69
author_rank: Super Contributor
timestamp: May 20, 2021, 08:49:06 am
content: In my estimation the price went up due to an opportunity to make more money.You will not replace a well equipped scope with this unit but an AD2 can be extremely useful on a bench for somebody starting out in electronics. As others have pointed out it offers a lot of capability.If I was just starting out today a scope would not be high on my list. This mainly due to getting by for a long time without. There is a real need for many tools to get started and frankly if you can get a lot of functionality out of one product, an AD2, it can save a student a lot of money. Which is why college students buy the unit.I'm still of the opinion that you should buy a scope when you can put down on paper what specs you need. That is you have increased your knowledge about electronic to the point that you understand where your interests are and what is required to help pursue those interests. In afterwords don't rush into a purchase. A scope can be a great tool to learn electronics so don't get me wrong there, but it isn't required to start out with the basics.Quote from: Lowkus on May 17, 2021, 09:17:42 pm

author: rstofer
author_rank: Super Contributor
timestamp: May 20, 2021, 01:50:40 pm
content: Quote from: james_s on May 20, 2021, 07:32:42 amThat's one thing that California got right! Prop 13 guarantees that the property tax is based on 1% the purchase price regardless of escalation plus a very few add-ons for specific purposes.Of course, that leads to unequal taxation for equivalent properties but so be it.https://www.sccassessor.org/index.php/faq/understanding-proposition-13In Silicon Valley we used to joke about selling our tract house here and having to buy a McMansion in Oregon just to avoid taxes on the capital gains. That's certainly changed!Today, a run-of-the-mill house in Sunnyvale is around $2 millionhttps://sf.curbed.com/2018/3/2/17073100/silicon-valley-house-home-sunnyvale-record-price-crisisThe "greater fool" theory is at work here!

author: Lowkus
author_rank: Regular Contributor
timestamp: May 20, 2021, 10:34:38 pm
content: I'm not sure how California does it, but property taxes in Washington are not based on the house price so much as it is the value of your home relative to the other homes. Hypothetical scenario, people in your county vote for some public project that will cost $200k per year, and lets say you have 200 homes in the county and they're all valued the same, each house has to pay $1000 in taxes each year (because $200k tax bill divided by 200 homes). If all the houses are valued at a billion dollars, each house still only pays $1000 in taxes. If all the houses are valued at $2.50, they each pay $1000 in taxes each year. Let's say our fictional county has only two houses in the entire county, both valued at $9.95, each of those homes will have a $100k property tax, because the $200k annual tax needs to get paid and it's up to those two homes to produce the money that's needed. Where things get imbalanced is when one home is worth $5 and the other home is worth $10, now the guy with the $5 home is paying 33% of the taxes due ($66,666) and the guy with the $10 home is paying 66% of the taxes ($133,333). It's all an issue of the ratio of what your home is worth relative to other homes. If your house goes up in value in the same proportion to all the other homes then your taxes really won't change much, it's only a problem when your home goes up in value while other homes don't go up. Or, more likely, your taxes are going up because people in your area vote for a lot of stuff that costs money, then those expenses get put right onto your property taxes.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 21, 2021, 09:05:52 am
content: Quote from: wizard69 on May 20, 2021, 08:49:06 amWhat kind of tools would you recommend someone purchase before an oscilloscope?

author: Anthocyanina
author_rank: Frequent Contributor
timestamp: May 21, 2021, 01:22:45 pm
content: Quote from: Lowkus on May 21, 2021, 09:05:52 am2 multimeters and a power supply should be super useful in helping you understand the basics of electronics and getting you started with building your own circuits

author: rstofer
author_rank: Super Contributor
timestamp: May 21, 2021, 03:54:25 pm
content: I would think a couple of DMMs (probably 3) would be on hand before worrying about a scope. If I were playing with a transistor common emitter amplifier, I would want to simultaneously measure Ib, Ic and Vce. For low end DMMs, low voltage only, I'm pretty fond of the Aneng 8008. Dave has reviewed it.I got along for decades without a proper power supply. Batteries work well, wall warts are another possibility. But, yes, a triple output power supply is handy. If you want to play with op amps, sooner or later you will need a +15 -15 supply and then some other supply for the rest of the project.Something like this might work well enough for op amp circuits:https://www.jameco.com/z/PD-2515-MEAN-WELL-Power-Supply-Dual-Output-Open-Frame-15V-1A-Negative-15V-1A-24W_2100857.htmlThe power supply issue comes up about once a week. Search...I did have some high current 5V supplies because, back in the old days, all I worked with was TTL. I didn't need analog circuitry, just 5V to feed the logic.Watch w2aew's videos and see which power supplies he is using. Most are ancient but affordable. Here's one example of a dual output supply with analog meters. You can always use one of your DMMs if you need more resolution for setting the voltage.https://www.ebay.com/itm/402528610597If I were trying to learn electronics (as opposed to cut-and-paste projects), I would be all over the AD2. The problem is, folks look at the small package and decide it is a toy. That's a really big mistake!Anyway, 'power supply' threads are about as common as 'which scope' threads. Search...The most common 'want' specification is 0-30V 3A (two channels) and 5V 3A. That's like a 200W space heater. With today's use of CMOS, there is no justification for such a supply. 1A goes a long way and you can easily build a 3 output supply with 7805,7815 and 7915 linear regulators. The regulators can also be used in circuits that are adjustable.https://www.eleccircuit.com/dual-adjustable-power-supply-circuit-diagram/

author: tunk
author_rank: Super Contributor
timestamp: May 21, 2021, 05:14:31 pm
content: And maybe a cheap component tester, something like an LCR-T4.Edit: Dave has looked at it:https://youtu.be/7Br3L1B80ow

author: bdunham7
author_rank: Super Contributor
timestamp: May 21, 2021, 06:19:54 pm
content: Quote from: Lowkus on May 21, 2021, 09:05:52 amWe'd need to know where you are at now and what you plan on doing in the near future. The more specifics the better. I started out planning on repairing and restoring old audio stuff and then found a source of used, broken test equipment and thought I could build up my equipment portfolio by repairing and selling test equipment and now I have a lot of stuff without any real expenditure. I also finally acquired enough stuff to properly service radios, which is probably a larger list of stuff than you might think going in.Fortunately I don't have to make a living at it--that is harder and probably less enjoyable. What are you doing now?

author: james_s
author_rank: Super Contributor
timestamp: May 21, 2021, 06:43:53 pm
content: Quote from: Lowkus on May 20, 2021, 10:34:38 pmI don't think that's true. My property taxes are based the tax assessed value of my house, which is typically below market value but still rises along with it. My house has not increased any faster than other houses in the general area but my property taxes have gone up by ~20% compared to last year, that's around $1200 a year out of my pocket and I don't have any more house than I had before. It is completely out of my control, the more people who flood into this area driving prices up the higher the direct cost to me. Expenses are rising a lot faster than income.

author: rstofer
author_rank: Super Contributor
timestamp: May 21, 2021, 07:14:15 pm
content: Take a hypothetical Washington neighborhood (as described above) with 3 properties worth $10,000 and one property worth $1,000,000. The 3 low end properties decide to vote for a massive project. They pay essentially nothing for the project and the high dollar owner pays just about all of it. Doesn't soundrightfair to me!Every election cycle, somebody takes a shot at overturning Prop 13. It is the ONLY reason that people aren't taxed out of their homes. In fact, old people being taxed out of their homes is the reason there was a ballot measure in the first place. I'm old and I have no intention of living under a bridge.Prop 15 was a losing attempt in the last election cycle to reassess the value of commercial property. Fortunately, it failed. Had it passed, it would be the first chip in the armor of Prop 13. Sure, it purported to affect only commercial property but that could change fairly easy. It may seem strange but politicians have been known to lie.One limitation of Prop 13, the net property tax can only increase by a maximum of 2% per year and, typically, Social Security increases by a similar number. A $1,000,000 property would be assessed a tax bill of $10,000 and it could only increase by $200 per year. Approximately...Of course, special projects can be approved by voters and will impact the tax bill. Sometimes school projects or fire districts are funded this way. It's not a big deal. The 1% and 2% numbers are what keeps people in their homes.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 21, 2021, 07:29:50 pm
content: I'm pretty sure my description of the tax situation is accurate, you can call up your local Department of Assessments and ask them how it works and they'll confirm. Well, I did gloss over a state education tax that does do a straight percentage from your assessed value, but that particular tax is a small percentage of your property taxes. Also you have to factor in what kind of business activity is going on around you, because businesses pay a personal property tax that goes into the same pool of money that residential homes are paying into, when the business go bust then more of the tax burden falls onto the residential home owners. Also there's a senior citizen exemption to reduce taxes for low-income seniors, which is good for the seniors but the money they avoid paying then gets put onto everyone else in the levy district.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 21, 2021, 07:46:51 pm
content: Quote from: bdunham7 on May 21, 2021, 06:19:54 pmI've been doing computer programming for about 30 years (VB.Net unfortunately, which doesn't translate to electronics as well as C/C++/C#). I've watched most of Dave's videos but my retention of the information is lackluster. My first project goal is to build a rotary encoder knob that changes the value displayed on an LCD. I expect most of my projects in the future will stay in the realm of digital audio generation, but I'd like to do some FFT processing for more advanced projects.

author: rstofer
author_rank: Super Contributor
timestamp: May 21, 2021, 11:43:21 pm
content: There are many Arduino projects using rotary encoders and LCD displays.https://www.seeedstudio.com/blog/2020/01/19/rotary-encoders-how-it-works-how-to-use-with-arduinoThis approach let's you take advantage of your C skills. Yes, the Arduino libraries are written in C++ but most of the user code will be written in C.There are better ways to do the encoder logic. My favorite is to get an interrupt on the level change on either pin in both directions (rising or falling). Then I use a state table to track the transitions and increment/decrement the count. This means I don't have to poll the encoder in the superloop - loop(). Obviously, if you just received a rising edge interrupt, you change the port around to look for a falling edge. The state table is responsible for making sure you don't count contact bounces.

author: bdunham7
author_rank: Super Contributor
timestamp: May 21, 2021, 11:52:48 pm
content: Quote from: Lowkus on May 21, 2021, 07:46:51 pmAn Analog Discovery and a nice breadboard would probably be a way better fit for what you want to do at the moment.Once you've made your circuit work, you can learn how to make a circuit board in KiCad.Then you are 90% of the way to having a complete 'product'.

author: Canis Dirus Leidy
author_rank: Regular Contributor
timestamp: May 22, 2021, 03:12:41 am
content: Speaking of digital logic. The price ofChinese clones of the eight-channel Saleae Logicon Aliexpress is about $10 (including delivery), and its capabilities are sufficient toview data exchange via low speed serial bus or PWM signal from microcontroller.

author: Old Printer
author_rank: Frequent Contributor
timestamp: May 22, 2021, 01:09:34 pm
content: It’s unfortunate that the price of the Analog Discovery has moved past a Rigol 1054Z, that makes it a very tough sell. It is truly the Swiss Army Knife of electronic T&M equipment, but without a knob or screen it takes a beginner with a good imagination to get past the current price. I assume they are dependent on college professors mandating it for course participation to maintain their sales. Glad I got mine when they were well under $300.

author: rdl
author_rank: Super Contributor
timestamp: May 22, 2021, 01:41:51 pm
content: Years ago I saw a post on another board that Newark was selling a thing called "Analog Discovery" for $99 as an "Engineers Day" special. They said it was a great deal and recommended everybody grab one. Without even knowing what it was, I bought one. Really happy I did now. But I agree that the newer version seems a bit pricey.

author: rstofer
author_rank: Super Contributor
timestamp: May 22, 2021, 03:18:48 pm
content: Quote from: Old Printer on May 22, 2021, 01:09:34 pmAt my grandson's university, the labs are set up around the AD2. You can provision for a lot of students when the educational price is about $100. More important, in the time of Covid and no in-person labs, students are just about compelled to provision their own lab. You really can't do EE courses without some amount of lab work.Somehow, a plot of the function Vo = Vin * (1-e-t/Tau) isn't as satisfying as actually seeing the waveform of the charge and discharge of a capacitor. Sure, I know the output is about 63% at t = 1 Tau but I really believe it when I see it on a scope. Not just an AD2 problem, any scope can display this result. You just need an appropriate source of a square wave and perhaps even the compensation test point would be adequate.

author: bdunham7
author_rank: Super Contributor
timestamp: May 22, 2021, 03:42:12 pm
content: Quote from: Old Printer on May 22, 2021, 01:09:34 pmI don't think there's much overlap between the AD and a Rigol scope. The OP seems to be comfortable enough with computer controls and a regular scope would probably be more limiting. The AD2 may no longer be a bargain, but it is probably a complete solution to the OPs needs, whereas with old-school instruments you need a scope, a power supply, a DMM, etc etc.

author: rstofer
author_rank: Super Contributor
timestamp: May 22, 2021, 04:00:55 pm
content: Quote from: Lowkus on May 21, 2021, 07:46:51 pmAlmost every modern DSO can do FFTs and so can the AD2. In my view, the AD2 does it better.When people talk about the utility of 4 channel scopes, they are usually talking about digital systems. They are using the scope as a logic analyzer with some amount of protocol decoding. The AD2 has 16 digital inputs/outputs and can be used as a 16 channel LA. Plus 2 channels of scope displaying either digital or analog. Or, some or all of the digital channels can be used as output to produce either patterns or discrete signals.I'm not sure you can get equivalent test equipment as inexpensive as the AD2 even at its new price. If resolution matters, just try to find a scope with a 14 bit ADC at anywhere near the price of the AD2. Same with the 14 bit waveform generator. The recommended scopes (SDS1104X-E and DS1054Z) have 8 bit ADCs. I can't convince myself that it matters because these old eyes can't separate the pixels on the screen anyway. Nevertheless, 14 bit conversion is better than 8 bit.There's no doubt that I am a huge fan of the AD2. I would always recommend it for people trying to learn electronics. There's a lot of capability in that little box.Download the Waveforms software and mess around with the Demo device. It's free!https://store.digilentinc.com/digilent-waveforms/

author: rstofer
author_rank: Super Contributor
timestamp: May 22, 2021, 04:06:19 pm
content: Quote from: bdunham7 on May 22, 2021, 03:42:12 pmAnd a competent arbitrary waveform generator. It seems that an ordinary signal generator just won't do these days. Even so, a decent signal generator is another cost and the AD2 has 2 channels of arbitrary waveform generator.I have yet to use the 'arbitrary' bit on my AD2 or my Siglent SDG2082X. It would be kind of cool to write up some Fortran code to produce values for some waveform. Nostalgia...The AD2 is actually a great choice in test equipment. Unfortunately, many think of it as a 'toy'.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 22, 2021, 04:19:09 pm
content: Roll mode displaying 4 channels of control voltages coursing around an analog modular synthesizer setup.Ch1: ASDR Amplitude envelopeCh2: Trigger pulses from chaotic event generatorCh3 and Ch4: smoothly varying control voltages from chaotic event generator

author: Lowkus
author_rank: Regular Contributor
timestamp: May 22, 2021, 09:49:44 pm
content: Let me flip the question and ask, what kind of projects would call for purchasing a Siglent SDS2104X Plus rather than the AD2?

author: bdunham7
author_rank: Super Contributor
timestamp: May 22, 2021, 10:11:38 pm
content: Anything with higher bandwidth signals or higher voltages than you are comfortable connecting to the AD2.Repairing an old AM/FM radio. Fixing or designing a mains-connected PSU. Actually any sort of repair probing or testing of existing devices would seem like the job of an actual standalone scope.If a circuit would not be appropriate for a breadboard, it probably isn't appropriate for an AD2. Or something like that.

author: ledtester
author_rank: Super Contributor
timestamp: May 23, 2021, 02:12:37 am
content: My two cents...Electronic design today mainly consists of integrating together well-understood circuits, and therefore the job of the designer really boils down to picking suitable components for those circuits based on performance, price, availability, physical dimensions, compatibility with the rest of the design, etc. That is, a lot of designer's time is spent reading datasheets or performing parameter searches for usable components.Coming from a software engineering background myself I realize that the design methodology is very different between the two fields. Prototyping in EE is done but not nearly as often as it is done in software engineering. Natually it's a lot more expensive in terms of time / effort / money, but, more importantly, even a working prototype doesn't necessarily validate your design. Physical components have variance and you have to take into account environmental conditions, etc. Just because one copy of the device works doesn't mean additional copies are going to work.The point is that a scope doesn't help much in designing applications. It is, however, very valuable in learning the electronics needed to read and understand what a datasheet is telling you. A scope + function gen (and a good text), for instance, can really help clarify the significance of all of the various parameters that are important for an op amp.I have a DS1054Z and I love it but it is easily the least used piece of equipment on my bench. My most used tools: my power supplies, meters, soldering iron and my Arduinos for digital waveform generation and GPIO. I've rarely debugged a digital circuit with a scope -- usually there are other ways to figure out what's going on. I've used a 4 meter setup multiple times to measure input and output power; having a DC clamp meter is so convenient because you don't have to break any connections to measure current flow. Debugging a failed circuit always begins by making readings with a multimeter. The operating principle behind most devices is very well understood and a few continuity and voltage checks goes a long way to narrowing down where the problem is.Ok, that's all!

author: MarkF
author_rank: Super Contributor
timestamp: May 23, 2021, 02:39:14 am
content: I haven't been following everything that's been discussed.However, the UNI-T UTG932E 30MHz, approx $100, may be an option for a separate signal generator.As a retired electrical engineer, I bought a Rigol DS1000z almost from the day they came out.I've been very pleased with it and would recommend it to a beginner.Unless you are doing some very special work, any of the Rigol or Siglent 100MHz scopes being discussedwould satisfy your needs for many years.The only thing I would recommend is a 4-channel scope. Four channels are almost indispensable whendoing serial decoding with micro-controllers (i.e. serial, SPI, I2C, etc.).

author: rstofer
author_rank: Super Contributor
timestamp: May 23, 2021, 03:03:27 am
content: Quote from: Lowkus on May 22, 2021, 09:49:44 pmI'll answer a completely different question: You need both if you intend to learn electronics. The question is, which do you need first?It's nice to have a Rigol DP832 Power Supply, a Rigol DS1054Z Scope, a Siglent SDG2082 Signal Generator and a Tektronix 485 350 MHz Scope plus an armload of DMMs. It took me a long time to get to this level of equipment. I don't have any idea how much it cost (I could add it up but I won't) and it is certainly more capable than the AD2. For the money, it better be!I could do most of what those combined instruments can do with just the AD2. With the optional BNC adapter board, I can use conventional X1/X10 probes which would allow for higher voltages but I give up the differential inputs on the ADCs. It's a choice... I bought a pair of fixed X10 probes just to prevent some kind of 'oopsie' at higher voltages. I don't use this adapter very much. Don't overlook the utility of differential measurements on the ADC inputs to the AD2. There are some interesting measurements that actually require this type of measurement. Voltage drop across a transistor base resistor (to get base current) is one such example. Same with Vce when there is an emitter resistor.There are frequency limits to the AD2 as well as voltage limits. The frequency limit is higher than the old 10 MHz Heathkit scope I used for years and years. I did some pretty interesting projects with that old scope. When I started fooling around with FPGAs, it was time to upgrade. But for the average Arduino project, a 10 MHz scope would be fine.When I said 'learn' electronics, I am thinking about the average lab exercises. I can take a 10k resistor and a 0.1 ufd capacitor and spend all day playing with them in the time and frequency domains on the AD2. I get a real appreciation for how a low pass filter works or how a capacitor charges and discharges. Same with transistor circuits, I can use the signal generator to provide the input and the scope channels to watch the input and output. There's some real education going on. Change the values, see if the new output is what you expect.It's one thing to see the plot in LTspice, it's quite another to see a real plot from a breadboarded circuit. Among other things, components have tolerances. That -3dB point won't actually be where it is calculated to be.I can use the impedance adapter to evaluate capacitors and inductors. There are some interesting things that go on with increasing frequency. The transistor curve tracer adapter is pretty interesting as well. These tools give you a real leg up on the learning curve.The only caveat: The device has very low voltage input limits. Be very careful and know what you are probing. Otherwise, use the BNC adapter and X10 or X100 probes.At $279, it was a pretty hard sell. At $399, it's a lot harder. I can see where people would be skeptical so I don't try very hard. It's a great tool but it's a giant leap of faith to actually buy one.All I can say is play with the Waveforms software and see what you think. The Demo device allows you to see some of the functionality. Just the list of tools is fairly impressive. There are 12 tools plus scripting. You can invent your own application specific tool if you wish.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 23, 2021, 03:59:50 am
content: I think $399 is the sticking point for me about the AD2. Maybe it's worth that asking price in terms of usefulness, but Digilent has profited from the device at lower pricing for several years, the technology in it has gotten cheaper since it was created, to my mind that suggests the market could easily have a competing product that is a better deal than the AD2. Is the competition hard to find because they are too small to have built a following, or is there some anomaly preventing competitors from duking it out against the AD2?

author: bdunham7
author_rank: Super Contributor
timestamp: May 23, 2021, 05:11:31 am
content: There is the Analog Devices version:https://www.mouser.com/datasheet/2/609/ADALM2000-Active-Learning-Module-1633739.pdfSupposedly the software isn't quite as good.

author: ledtester
author_rank: Super Contributor
timestamp: May 23, 2021, 05:24:15 am
content: $399 vs $280 is only $120. You can get a used AD2 on ebay for around $280. I was able to get a used AD1 for about $120 back last fall. With the school year ending perhaps more AD2's will come on the market.About the hardware being "old"... perhaps the hardware hasn't changed much since it first came out, but the real value of the AD2 (and test equipment today in general) is in the software available for it. Consider all of the options you can unlock in a scope for more money. The hardware hasn't changed -- you're just paying to use some new firmware. And when it comes to programming, value can also be measured by how easy it is to get the device to do what you want -- i.e. support from the vendor, from the community, etc. There are some offerings which kinda compete with the AD2 -- such as the ADALM2000 and some Picoscope offerings -- but they don't have as large of a following. And the AD2 still has better hardware specs than either of them.

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2021, 07:14:15 am
content: Quote from: Lowkus on May 23, 2021, 03:59:50 amSame price as a 4ch SDS1104X-U with 400V rated inputs.

author: rstofer
author_rank: Super Contributor
timestamp: May 23, 2021, 02:48:26 pm
content: Quote from: ledtester on May 23, 2021, 05:24:15 amThere's one on eBay right now for $834https://www.ebay.com/itm/284262440099

author: bdunham7
author_rank: Super Contributor
timestamp: May 23, 2021, 04:17:40 pm
content: AD1 is pretty much the same device lacking only variable power supplies. If you buy the Digilent breadboard for $25, you can add on a 3.3V powerbrick and that issue is solved.https://www.ebay.com/itm/203400805474?hash=item2f5ba1fc62:g:3Z0AAOSwqMlgiActThat's still a bit more than before, but hyperinflation has arrived, so....

author: alsetalokin4017
author_rank: Super Contributor
timestamp: May 23, 2021, 04:27:40 pm
content: Oh yeah, probes. If you buy a new oscilloscope, it will of course come with usable probes of matching bandwidth ratings, one for each channel, generally with switchable 1x-10x attenuation.I don't know if the Analog Discovery units come with probes.

author: james_s
author_rank: Super Contributor
timestamp: May 23, 2021, 05:26:05 pm
content: I don't think it does, but a decent set of inexpensive probes that will more than cover the bandwidth it offers can be had for under $15 shipped so it isn't something I'd worry about.

author: rstofer
author_rank: Super Contributor
timestamp: May 23, 2021, 06:56:25 pm
content: The AD2 BNC Adapter does not come with probes. Digilent does sell a set of x1/x10 probes for $20. I have a bunch of x1/x10 probes laying around. But...I bought a set of fixed X10 probes from ProbeMaster because I can't possibly have them set to X1 when working on higher voltages. These were very pricey so look around for something else but do consider buying fixed X10 probes. No matter how much they cost, they are cheaper than a new AD2.The AD2 itself is rated +-25V. This clearly covers my maximum range of +-15V but for those working at higher voltages, the X10 probe should cover +-250V.We have 14 bits of resolution so using x10 probes at lower voltages doesn't give up much.There is no way I'm going to use my AD2 on mains powered projects. Then again, I'll probably never work on such a project.

author: james_s
author_rank: Super Contributor
timestamp: May 23, 2021, 06:58:52 pm
content: I hate the fact that almost all of the inexpensive probes are switchable 1X/10X, I have never once that I recall used the 1X mode on a probe and I sometimes glue the switch so it will never accidentally get changed. I don't know why they make them like that, it has to cost more to produce than a fixed 10X probe and it is a feature that is useless to most people.

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2021, 09:16:20 pm
content: Quote from: james_s on May 23, 2021, 06:58:52 pmRecently I went looking for a selection of fixed 10x autosense probes and found 100 MHz ones for just $15ea ex supplier so they are available if you do your homework.350 MHz ones were $40 which is quite reasonable compared to what's wanted from most scope manufacturers.Models if you want to hunt for them yourself:CP-3101RCP-3351R

author: tatel
author_rank: Frequent Contributor
timestamp: May 23, 2021, 10:08:24 pm
content: If you are thinking in electronics as a way to earn your living, Siglent SDS-2104X+ oscilloscope would be the way to go, I think. In the long run, you'll probably want plenty of bandwidth and samplerate, and a MSO option. That scope has it all, and more. Enough to do quite a long way. I myself have been on the brink of buy it.However, since you said you are an absolute newbie and don't know even what you want to do exactly, I think there are better ways to invest your money, so you'd are able to learn more, faster. After some learning, you'll be able to make more educated decissions. Going for an expensive scope (or any other stuff) right now could be a worse way to go. Some suggestions:Oscilloscope: I guess you know about the 5X recommendation. So, ideally, if you are going to deal with, say 20-ish MHz signals, you want at least a 100 MHz, 500Msps/channel scope. Siglent SDS-1104X-E can do that with all four channels, yet you could do even with less scope and save some more bucks to invest them in other things that will come in handy.You could also consider having an scope with MSO option. Perhaps the Rigol DS1074Z+ could be adecuate, but be aware that using the LA pod in this scope will disable two analog channels. Even so, it could be good enough. SDS-1104X-E LA pod doesn't work fine. If you search the forum, you'll find people unhappy with this. Anyway, this would put you in the $700-800 range, and a lot of people will say to you it isn't worth the money, and that you'll be better with a cheaper scope and a separate logic analyzer. Considering your current situation, I would agree.Logic analyzer: Saleae clones are dirty cheap, and will get you started. You could also get a 400 MHz, 16-channel DSLogic Plus for some $100. Hacking the basic model doesn't save you a lot of money because the good cables will cost you that money anyway.Function generator: You can output quite a bunch of signals out of an arduino. A GM328 transistor tester has this arduino, can identify a lot of components, and can output the same bunch of signals, for some $20. UNI-T UTG932E looks good, Rigol DG811 is double the price but it is a pro-entry-level device.Lab power supply: You can do a lot of things with linear regulators and learn, but probably a linear, 30V, 5A would be handy and make you able to do quite a lot more things than just linear regulators.Soldering iron/Rework station. I bought a Yihua 853D 3-4 years before getting into this forum. For some €125 it has soldering iron, hot air gun and a 15V, 1A power supply. It was enough to get into the game and desolder chips from cell phones, etc. But I have to set it to at least 300ºC to get the soldering iron working acceptably, and now both the iron and the air gun are about to die. Not that I have worked it so much. So perhaps a guy would be better buying something like a Hakko FX-888D soldering iron, and maybe a Quick 861DW air gun, or some similar thing.What about inspection stuff? Are your eyes the same they were years ago? ESD stuff? Will you need to buy components to play with them? All this stuff -and more- will do more for you right now than an expensive scope.Finally, I guess you already watched this, but, just in case, probably there is no better advice than...https://www.eevblog.com/2016/12/11/eevblog-954-how-to-setup-an-electronics-lab-for-300/https://www.eevblog.com/2011/04/30/eevblog-168-how-to-set-up-an-electronics-lab/Edit: typos and non-native speaker details

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 23, 2021, 10:16:32 pm
content: Any scope is better than no scope. Even the crappiest piece of junk from Aliexpress. My only caveat would be a minimum of 2 channels.As a beginner, being able to look at waveforms etc. will improve your understanding of what is going on enormously, not having one will just cause frustration and hinder learning.Once you get more advanced, you will understand the limitations of what you have and can make a better decision on what to spend money on for something more serious.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 24, 2021, 05:16:16 am
content: I just remembered I was planning to troubleshoot a PCMCIA Type1 port on an old synthesizer I have (Alesis Andromeda). The synth can read and write to one Type1 card I own, but has failed to consistently work with other cards I've plugged into it. I managed to find one card that worked for a couple of weeks flawlessly but then suddenly it was erased and sporadically dropped connection. The synth is known to be extremely finicky about which cards work on it, down to cards made by specific manufacturers, so I'm figuring Alesis was straying a bit outside the PCMCIA specifications, or it's possible my synth has an electrical problem at the port. If my research is correct then the PCMCIA Type1 data is sent in parallel at 133 MB/s. If that's the case then what kind of oscilloscope bandwidth would I need to inspect the data going across that port?

author: tatel
author_rank: Frequent Contributor
timestamp: May 24, 2021, 10:18:09 am
content: Oh, man. Please see this thread:https://www.eevblog.com/forum/testgear/busses-serial-links-and-required-scope-bandwidth/msg873252/#msg873252Be aware that these are serial buses. Being parallel, frequency would be lower.http://www.interfacebus.com/Design_Connector_PCMCIA.htmlSo, if it actually works at ISA speeds (10 MHz), the cheapest scope would do... but I fear you'll be running out of channels.I have no clue about what you could do. Perhaps somebody with much more knowledge than both you and me can give you a good answer.

author: rstofer
author_rank: Super Contributor
timestamp: May 24, 2021, 01:39:48 pm
content: Quote from: Lowkus on May 24, 2021, 05:16:16 amThere are two things to consider: First, signal integrity. Are the squiggly lines reasonable on the edges and along the top/bottom. This implies a scope but it doesn't require all lines to be tested simultaneously. If the signal speed is on the order of 33 MHz, you would ideally have a scope with at least 7 times that frequency in bandwidth. Perhaps an SDS1104X-E unlocked to 200 MHz.Second, the transactions. Here, a Logic Analyzer is a better tool. Get something that will sample at a couple of hundred MHz and have as many channels as you can afford. You don't have to watch every data line and every address line at the same time but you should be able to display a few of each along with all of the control signals.I have no idea how you plan to attach to the signal lines. There are breakout boards but they are expensive.It's not the same bus but when I had a problem using an Compact Flash card with an FPGA, the reason was the fast transitions of the FPGA causing reflections on the signal lines. The solution was to add 330 Ohm resistors in series with every signal.

author: bdunham7
author_rank: Super Contributor
timestamp: May 24, 2021, 05:05:38 pm
content: Quote from: Lowkus on May 24, 2021, 05:16:16 amWell that's an ambitious first project! I would suspect that there is something with the synth that is out of step with the rest of the PC Card world. You should have 16 lines with a max frequency of 33MHz, which seems well within the capabilities of many entry-level scopes, but you have to be careful with circuit loading so selecting proper probes is important. I suspect there is either an outright misdesign in the signal circuitry like rstofer's example or the logic voltage levels are not the same as other devices. Even if you figure out the issue, I'm not sure how you would repair it if it is a design problem. I think there were widespread issues with standardization in early PC Cards. You might be better served by tracking down an appropriate card and paying whatever ransom is required. I remember several automotive diagnostic tools from that era that used PC Card and attempts to substitute generic cards for the OEM ones often didn't work out.EDIT: No guarantees, but one of these two adaptersmightallow you to use a CF-card with your synth. These adapters might just be more tolerant than the original PC Cards. Most CF-to-PCMCIA adapters will not work, but these are different.https://www.ebay.com/itm/324449998675?hash=item4b8aba1753:g:2Z0AAOxy9nhSJgzmhttps://www.ebay.com/itm/CF-Card-to-PCMCIA-ADAPTER-TYPE-1-for-Laptop-Compact-Flash-Janome-Elna-Free-Ship-/183661994333

author: Lowkus
author_rank: Regular Contributor
timestamp: May 24, 2021, 05:38:41 pm
content: Yeah, too ambitious for a first project, I was just trying to think ahead at what equipment capabilities I'd need when the time came to tackle it a year or two from now. Rstofer's comment about the signal reflections was a good reminder that my skills are not quite there yet, I'd have no idea about that if I was troubleshooting today. What's interesting in terms of equipment though is that it seems like if you never know what project you're going to work on then you'd almost have to buy progressively more powerful equipment. Pictures of engineer's labs are often filled with tons of equipment, is it gear acquisition syndrome where they are buying new toys to use even though they could get by with what they have, or is it built up because they repeatedly have to buy faster/better/stronger gear that will match the increasing difficulty of their projects?

author: Robert Smith Eco Warrior
author_rank: Regular Contributor
timestamp: May 24, 2021, 06:01:15 pm
content: Quote from: james_s on May 23, 2021, 06:58:52 pmAh... that may explain why the switch on the probe that came with my oscilloscope is a bugger to turn.

author: rstofer
author_rank: Super Contributor
timestamp: May 24, 2021, 06:36:24 pm
content: Quote from: Lowkus on May 24, 2021, 05:38:41 pmThey show up as ringing in a scope trace. Hopefully, the probe doesn't load the signal so much that the reflection only occurs when not probing. Ringing wasn't my first thought with that project either. The thing about FPGAs is that they are FAST.QuoteClearly, you don't buy a multi-GHz scope to fool around with Arduinos. When you get to the point where you are working at frequencies beyond your test equipment capabilities, you buy something else. Or work at lower frequencies. Keysight makes a scope that costs $330,000 plus accessories. I'm not in the market...Really, that's why we're talking aboutentry level scopes. The more inexpensive scopes that are adequate for a good long time. We're all aware of the limitations of entry level scopes and don't feel that we need something more capable or we would mortgage the house and buy something else.

author: james_s
author_rank: Super Contributor
timestamp: May 24, 2021, 07:51:46 pm
content: Quote from: Lowkus on May 24, 2021, 05:38:41 pmA lot of people just like collecting gear, look at anybody who is an enthusiast and has been into something for a while and they will probably have accumulated quite a large collection of related items. More serious professional engineers will typically buy a new piece of gear when they need it for a specific project, or they too might just see something that looks like a fun toy and decide to upgrade if their budget allows.You can never have too much bandwidth, or too many channels, just like you can never have too much bench space, too much storage, too big of a workshop, too much land, too big of a boat, too much memory in your PC, too much money in the bank, etc. No matter how much you have there are times when you're going to wish you had more. All you can really do is buy what you can afford that will meet your needs now and hopefully a little into the future, don't become paralyzed with indecision based on what you might need some day. It is only very recently that we even had the luxury to think about this, 20 years ago a 100MHz DSO would have been well out of budget of all but the most serious hobbyists. When I got into electronics as a kid even a 20MHz analog scope was something I could only dream of owning.One thing to remember with these budget scopes is they hold their value very well. Look on ebay for sold examples of a scope like the DS1054z, not asking prices but actual sold items. You will find many used ones that sold for nearly as much or in some cases even more than it costs to buy a brand new one from a place like Tequipment. Whatever you buy, take good care of it, don't be careless and fry it or let it get all beat up. Save the box and all of the odds & ends that come with it and if you later decide you need to upgrade you can probably get back most of what you spent on it by selling it to someone else. This does not have to be a major life decision and long term commitment. You don't have to buy the scope today that you will use for the rest of your life.

author: Lowkus
author_rank: Regular Contributor
timestamp: May 24, 2021, 08:34:45 pm
content: While I'm pondering on this oscilloscope advise, I should probably order a couple of DMM's. I'd like to support EEVBlog by buying the branded units, is there a good reason to choose one over the other in looking at the 121GW or the BM786? Is it best to own two of the same model to have accurate comparison of the measurements, or better to get two different models for some reason?

author: bdunham7
author_rank: Super Contributor
timestamp: May 24, 2021, 08:53:39 pm
content: Quote from: Lowkus on May 24, 2021, 05:38:41 pmBoth reasons apply. It's not easy to equip yourself in anticipation of some need that you don't fully understand. For example, if instead of PCMCIA you had a problem with an LVDS circuit, you might use $15K+ in probes plus an oscilloscope that costs as much as a nice car to scope it:http://cdn.teledynelecroy.com/files/appnotes/lab1012.pdfThere are some basic things that you can get relatively affordably that will always be useful at almost any level--DMMs, AWGs, PSUs. OTOH, Oscilloscopes and spectrum analyzers start getting very expensive once you move beyond the 'prosumer' level, which is one level above 'entry'. Those are the sorts of things that some of us are perpetually scrounging for.QuoteOne of each, of course! There's no particular reason to own two of the same model. Having different ones just makes it more possible that one or the other will have a feature you need that the other lacks. I see the 121GW is quite cheap today on Amazon. The BM786 looks expensive, maybe wait for a deal.

author: tautech
author_rank: Super Contributor
timestamp: May 24, 2021, 09:08:47 pm
content: Quote from: Lowkus on May 24, 2021, 08:34:45 pmPersonally I would steer away from a 121 and get the BM235 and maybe the 786.

author: Old Printer
author_rank: Frequent Contributor
timestamp: May 25, 2021, 02:38:36 pm
content: OP - Since you are not in a particular rush for a scope, I would hound Craigslist - OfferUp etc for one of the black case original AD1's. It will do 95% of what an AD2 will do and there were a lot of them sold to EE students for $99 back a few years before the program was cut. Once they hit ebay they are likely to get expensive, but CL & OU are a bit under the radar. I picked one up a couple years back for $50 on ebay. When you are not in a hurry, deals appear.

author: rstofer
author_rank: Super Contributor
timestamp: May 25, 2021, 05:06:52 pm
content: I have both the 121GW and the BM235 versions and they are excellent. I don't use them very often... I also have a Fluke 189 that doesn't get much use. And some others...For me, those meters are 'clubby'. They stand up pretty well but they are big and awkward when compared to a pocket size meter like the Aneng 8008 which is my preferred meter. Besides, I can buy a bunch of 8008s for the cost of the Fluke. Dave has done a review of the 8008.I also have a couple of 'bench' meters that don't get much use. They have the advantage of having a fixed place to park so size and weight doesn't become an issue. Somehow, it is just too much effort to use these to verify a resistor value. Or verify Vcc...I am of the opinion that you need at least 3 DMMs and they need not be all the same. I would certainly include the 8008 in the mix.

author: james_s
author_rank: Super Contributor
timestamp: May 25, 2021, 06:07:36 pm
content: Quote from: Lowkus on May 24, 2021, 08:34:45 pmI hear a lot of people recommending multiple DMMs but personally there is one handheld meter that I use 99% of the time and then I have a bench meter that lives on my bench, and I have a few other random meters that have accumulated but I almost never use those. There have been times that I've used two meters at the same time but it has been very rare and I personally would not run out and buy more than one multimeter.

author: rdl
author_rank: Super Contributor
timestamp: May 25, 2021, 07:12:07 pm
content: I have a Fluke 87-III but I don't recall turning it on since I got the Aneng 8008. I also have a RSR M9803R bench meter (rebranded Mastech) that gets used quite a bit. I like a bench meter because they can sit on a shelf out of the way and don't need batteries.

author: rstofer
author_rank: Super Contributor
timestamp: May 25, 2021, 08:40:14 pm
content: Quote from: james_s on May 25, 2021, 06:07:36 pmI was thinking about educational projects. I would find it handy to measure base current, collector current and Vce simultaneously if I were studying transistors.Every day? One meter seems adequate most of the time.

author: wizard69
author_rank: Super Contributor
timestamp: May 26, 2021, 01:19:47 am
content: Quote from: Lowkus on May 21, 2021, 09:05:52 amI've been OTL for a few days so I read through the thread before coming back to this question. You have gotten lots of good ideas and comments so I'm going to take a wider approach. I'm assuming you are absolutely new to this so if not there are things you can self delete. So think of this as somebody that wants to start at the very beginning, the equivalent of Electronics 100.The Instrumentation:A good multimeter DMM! That means neither low end nor high end just a decent meter with a good display.A low end VOM. I know in this digital world people might rebel at the idea but I look at a VOM as another way to learn concepts in electronics.A power supply. I highly recommend a DIY fixed voltage unit using 3 terminal regulators. This is part of the learning experience and can serve your interests for now. The alternative is batteries or wall warts.The Works SpaceYou will need a decent works space which means some sort of bench, ideally in a dedicated area. Ideally that bench will have storage space either built in or adjacent to the bench. You will also need a comfortable chair.The LightingI have this separate from the work space because I see it as extremely important especially for repair. This includes room or ambient lighting and task lighting.The "Tools"A soldering station / iron.A set of screwdrivers.Needle Nose pliers.Diagonal cutters.A Panavise.Test leads, patch cords.A breadboard (not a cheap one).A magnifier.DocumentationThis is so easy these days I only list it here for nostalgia.TextsFind NEETS {Navy Electricity and Electronics Training Series} if you want something free.Frankly I'm too old to suggest something new, as an introductory students text. Hopefully somebody can give you a current title that is modern.For library fill out: The Art of Electronics

author: james_s
author_rank: Super Contributor
timestamp: May 26, 2021, 01:51:41 am
content: For the multiple DMM situation if you want that there's the option of one good meter and a couple of cheapies. Even the $5 Harbor Freight meters that you can occasionally get for free are adequate for measuring voltage in low voltage circuits. I wouldn't use one on line voltage or electric car batteries or something but for hobby stuff they're fine. A comparable meter when I was a kid in the 80s would have been the equivalent of $100+, all I could afford back then was a basic analog VOM. It's amazing what you can get now.

author: Old Printer
author_rank: Frequent Contributor
timestamp: May 26, 2021, 11:04:04 pm
content: I picked up an 8008 when they first came out, I think I paid $9 shipped. I really bought it just to see if it would actually show up, but it did, in a week, and became my go to meter on the bench. I just ordered a 2009 on AliExpress for $22, the best price I could find. They really are great little meters, and if someone says gee I wish I had a meter, you can had it to them and be a big shot for a few bucks