[sdiy] Starting Point?
Oren Leavitt
obl64 at ix.netcom.com
Mon Oct 12 06:40:53 CEST 2020
+1 on the Tek 22xx. Been using a 2215A for 30+ years with no problems,
except for replacing a capacitor in the CRT high voltage section.
Tek 465 is nice too.
- Oren
On 10/11/20 9:49 PM, BrightBoy wrote:
> If you're going to buy a used scope, it's hard to beat the Tektronix 22xx line.
>
> I know Paul Schreiber (MOTM) is rather fond of the 2230A.
>
> I have a 2246 that I got at a pawn shop for $100
>
> Cheers,
>
> Jeff
>
> -----Original Message-----
>
> From: Pete Hartman
> Sent: Oct 11, 2020 12:01 PM
> To: synth-diy at synth-diy.org
> Subject: Re: [sdiy] Starting Point?
>
> I made do with a DSO quad for about 8 years. I used a community firmware so it had a bit more capability than the stock version (most frequently used was a frequency analyzer, after the main scope function). I only stepped up to a Rigol 1054 this year; didn't quite have the $500 for the Sigilent.
> Biggest problems with the DSO were the tiny probe connections (which periodically broke on the probes) and toward the end, the battery life. But having a workable scope the size of a cellphone was nice.
> I do understand the idea of the best tools you can afford, but you can go a long way with good enough tools.... I still haven't upgraded my iron from the sparkfun hakko knock off that I started with (though I replaced it with a duplicate once, and repaired it a second time).
> I have an analog Tek scope too. I almost never used it because getting it lined up and in range was a pain. And it took up so much space.....
> Pete
>
> On Sun, Oct 11, 2020 at 10:38 AM Roman Sowa <modular at go2.pl> wrote:
>
> Even $10k scope has offsets, that's what autocalibration is for.
>
> Joy to use - probably not, as this is pocket size device. Can't
>
> imagine knobs on such a thing. Either the size/portability or ease
>
> of use. Trigger - exactly the basics of trigger in low end analog
>
> scopes.
>
> To have very good usable scope, there's at least $500 to spend.
>
> Indeed for that price what you get is amazing, hard to imagine
>
> what could anyone dream more for regular synth diy. If someone is
>
> serious about entering into electronics DIY, then go and buy
>
> Siglent SDS1000. But if not so sure yet, and the budget is tight,
>
> there's no other choice than handheld toy scopes.
>
>
>
>
> For a beginner it's bad idea to buy any old gear in bad shape.
>
> After all, how can they fix it if they are begginers, right? And
>
> if they have someone around more skilled to fix it, then the same
>
> person can borrow their equipment, or tech them, or most of all
>
> personally recommend suitable gear. I doubt any "skilled friend of
>
> a beginner" would like to fix such a thing for a pack of beers.
>
> And no, I haven't forgot how it was to be a beginner, I clearly
>
> remember those days. Even clearer than what I was doing last year.
>
> And I can't compare using toy scope to playing violin while
>
> standing on one toe. That is more like sitting on a sofa and
>
> playing PSP. Yes, I sometimes play with such scope in similar way
>
> as other people waste their time twiddling their phones.
>
> All I'm saying, if someone makes simple circuit on a breadboard,
>
> and it doesn't work, it's end of story. A multimeter will not show
>
> a fraction of what a scope can do. And maybe I'm patronizing now,
>
> but I bet that first circuit made by total beginner might possibly
>
> not work the first time. Without toy scope that means the circuit
>
> goes to garbage, and disapointed beginner looses interest in
>
> electronics and becomes fashion influencer or minecraft youtuber.
>
> What a loss.
>
>
>
>
> Now to be more specific, my one-line comments about some models:
>
> DSO138 - unbelievably cheapest option, good for audio, terrible
>
> use interface
>
> DSO112A - touchscreen yeah! And sqr generator inlcuded. Much
>
> better, but usable only in mid range of timebases
>
> Fnirsi 2031 - ready to use in 2s! Good enough user interface,
>
> actually can't remember what's so bad about it.
>
> Fnirsi 1013 - if not one thing it would be the best handheld
>
> scope ever created - it pretends to be low noise by some nasty
>
> unpleasant trick. And it is way more outrageous than aliasing.
>
> I'll share detailed findings if anyone's interested. But it's
>
> slightly over $100 anyway.
>
> There's so many more to try yet, but the above list presents
>
> basicaly full range of them. Other popular variants like 150,
>
> 5012, 6100, 6020, 1C15, 1511 etc. always look similar (in
>
> appearance, size and specs) to one of those listed here.
>
>
>
>
> Roman
>
>
>
>
> W dniu 2020-10-11 o 15:05,
>
> sleepy_dog at gmx.de pisze:
>
>
>
>
>
>
>
>
>
>
>
> I've seen some of those < 100 $ scope things that had DC
>
> offsets, lacking coupling options, total garbage trigger
>
> implementation and problems like that that make it not exactly a
>
> joy to use, "entry level" or not.
>
>
> Haven't looked at them for years. If you have an extensive
>
> collection as you say you are more likely to have come across
>
> ones that are decent - but is that a neutral view of the average
>
> implementation you are most likely to get, or undue bias from
>
> the ones you did like and use?
>
>
>
>
>
> I guess one could make a list of "known usable" ones, but such a
>
> list would become obsolete very quickly as things are today with
>
> all this no name gear and endless copy of a copy of a product,
>
> with the goal of further reducing the cost while being able to
>
> sell the appearance of a known product for a better margin.
>
>
>
>
>
> Sure, a old reputable-brand analog scope can be in bad shape,
>
> totally decalibrated I guess - maybe in that regard it's also
>
> risky to buy one as a beginner?
>
>
> Although sometimes they throw those out for (almost) nothing :)
>
> If one who got such a thing could get some friendly EE to look
>
> at it if it's basically OK...
>
>
>
>
>
> I'm not even saying specifically that alising thing really
>
> affects anyone in reality, IDK, just wanted to thrown in a bunch
>
> of possible examples of how one could add confusion or other
>
> aspects that might deter a beginner.
>
>
> Maybe you forgot how it can be as a total beginner because it's
>
> so long ago for you. Stepping into a field with a lot of loose
>
> ends in the mind and trying to make some connections and make
>
> abstract principles you just read about become intuitive.
>
>
> Gear doing funny things, it seemed to me, could disrupt that
>
> process. (sure, at some point, observing unexpected things is
>
> important to learn beyond the clear cut introductory textbook
>
> examples - but in the very beginning?)
>
>
>
>
>
> So the violin thing doesn't seem like a proper analogy.
>
>
> You want people to learn violin - but standing on one toe
>
> instead of sitting on a chair.
>
>
> Bending a learning curve to your disadvantage is not virtuous.
>
> The thing that is a virtue about putting in effort to learn
>
> something is not the spending of the effort itself, or scrubbing
>
> the floor with a toothbrush would be the most virtuous thing
>
> ever.
>
>
> AGAIN - maybe my examples of problems with toy gear weren't
>
> good... but I'm not sure they are the only possible problems
>
> with these wild east products whose essence seems to be
>
> fluctuating all the time.
>
>
>
>
>
> As you say, such gear are tools for thinkig humans - already the
>
> good ones. Maybe bad gear is ramping up the difficulty level?
>
>
> That's what I was trying to get at with maybe not the best
>
> examples.
>
>
>
>
>
> OKAY, and perhaps I also just find it hard to believe that some
>
> < 100 $ thing of that class of instruments can be decent
>
> enough.
>
>
> Just a couple years ago a 500 $ scope was looked at with
>
> suspicion, and I bought one due to lack of options ;) (and it
>
> did have some issues)
>
>
> And I don't think I'm quite the oldest fella on this list here -
>
> but it still seems just like yesterday. Ok, maybe I'm starting
>
> to get old :D
>
>
>
>
>
> Sorry for the long and perhaps boring text.
>
>
> I just really do like to sort out how my perceptions came to be
>
> as they are and them not aligning with the basic sentiment put
>
> forth by you.
>
>
> I get it I'm only a lowly hobbyist, and worse, one that has
>
> roughly a million other hobbies and just can't frickin stick to
>
> one :D
>
>
>
>
>
> - Steve
>
>
>
>
>
> Roman Sowa wrote:
>
>
>
>
>
>
>
>
> Yes, really.
>
> Signal amplitude of interest is well covered. You don't need
>
> 500V/div in a scope. Analog front end is adequate to the scope
>
> bandwidth which go up to some 30MHz in those toys. Maybe
>
> missing those 1mV/div settings in some models, but who needs
>
> that for entry level DIY? The old analog scopes were usually
>
> 5-20MHz and bandwidth was not the weakest pont anyway. First
>
> 100MHz analog scope I saw was big heavy and noisy Russian
>
> machine in mid 90's.
>
> Aliasing in digital scopes is a thing and anybody using it is
>
> aware of that. It's mentioned everytime someone says
>
> "oscilloscope". I think a newbie first learns about aliasing
>
> before knowing what an oscilloscope is. It's like saying you
>
> can't work with high voltage because it can shock you. There
>
> is no scope that prevents aliasing, no such thing as antialias
>
> filtering in any scope, including top range of top brands,
>
> because it's limiting and useless. Just like there's no scope
>
> with a button "show me what's wrong with this signal". A scope
>
> is a tool for thinking human.
>
> A violin will not play by itself either and if you don't know
>
> how to play, it will only make terrible noises, even if it's
>
> $1M Stradivari.
>
> Roman
>
>
>
>
> W dniu 2020-10-10 o 11:01, sleepy_dog at gmx.de pisze:
>
>
>
>
>
>
>
>
>
>
>
> > small toy scopes for below $100. And frankly they are
>
> better than big 50kg scopes I had in school
>
>
>
>
>
> Really? Including the analog front end, signal amplitude it
>
> can take, coupling options etc?
>
>
> And those old clunky analog scopes in school certainly did
>
> not fool you with aliasing due to improper filtering esp.
>
> when sample rate drops on long time base with ridiculously
>
> low k(!)points memory depth (like also "cheaper" *cough* Tek
>
> DSOs just a couple years ago), making you see things that
>
> aren't there.
>
>
> Those below 100 bucks scopes also usually have a very low
>
> sampling rate to start with, right?
>
>
> (don't "need" so high frequencies in synth DIY? Well, the
>
> *intended* frequencies that your DIY circuits *intentionally
>
> oscillate* at may perhaps not need that... :D)
>
>
> Sure, he can watch a video like below and then know about
>
> that one thing.
>
>
> It seems to me when entering a subject with a million
>
> questionmarks, adding more confusing stuff one has to be
>
> aware of might be disorienting.
>
>
>
>
>
> https://www.youtube.com/watch?v=uWADu0aKk0w
>
>
>
>
>
>
>
>
> - Steve
>
>
>
>
>
>
>
>
> Roman Sowa wrote:
>
>
>
>
>
>
>
>
> Totally agree.
>
> What may not seem so obvious, there's a catch - when you
>
> can afford all the fancy tools you dream of, then suddenly
>
> your creativity drops down the floor. With crappy tools
>
> you have to be more creative and think, imagine, explore,
>
> experiment. For example soldering - you have to learn how
>
> to solder anyhow, and cheap soldering iron is not
>
> forgiving, so it will force you to think what you're doing
>
> and be totally aware of what to do in certain situations.
>
> I have bought my first temperature controlled station
>
> about 20 years after I started soldering. Only because of
>
> that I could appreciate it. In case you wonder, yest it's
>
> possible to succesfully solder SMD with transformer
>
> soldering gun.
>
>
>
>
> The scope is essential, I think even more than
>
> multimeter, but today you can buy small toy scopes for
>
> below $100. And frankly they are better than big 50kg
>
> scopes I had in school. I have quite a few of those toy
>
> scopes, this is my small addiction, so if you want to ask
>
> about specific model, I probably have that. Don't buy
>
> "best scope you can afford", or "scope planned for the
>
> future". Those times are over. Now there's new scope
>
> coming every year, cheaper and better than others. After
>
> 2-3 years you'll know what to look for, and it will be
>
> more GAS hitting than real measurement needs.
>
>
>
>
> It is very unpopular point of view here, but I think
>
> modern digital scopes are much better that vintage analog
>
> Tek.
>
>
>
>
> Roman
>
>
>
>
> W dniu 2020-10-10 o 01:49,
>
> Peter Pearson pisze:
>
>
>
>
>
>
>
>
> While I agree that spending $1k will
>
> definitely get you set up, we aren't all so lucky.
>
> Especially when we're spending money made mowing lawns
>
> or working minimum wage as a youngster. What I meant
>
> was that a quality iron will really make the biggest
>
> improvement. That plus an "it works fine" multimeter
>
> and a working 20MHz oscilloscope used is almost all you
>
> need (less parts but that's subjective) to do some
>
> damage. Take the price point down from $1k to something
>
> more like $200-$300 or less and that's attainable for a
>
> lot of people.
>
>
>
>
>
>
> Something like this:
>
>
>
>
>
>
> https://www.youtube.com/watch?v=HicV3Z6XLFA
>
>
>
>
>
>
>
>
>
> BUY USED!
>
>
>
>
>
>
> You can work up to a $10k oscilloscope or whatever
>
> once you need one.
>
>
>
>
>
>
>
>
> On Fri, Oct 9, 2020 at
>
> 7:36 PM Benjamin Tremblay via Synth-diy <synth-diy at synth-diy.org>
>
> wrote:
>
>
>
>
> I learned this
>
> stuff as a kid through trial, error, burned fingers,
>
> and Radio Shack. I never had more than ten or so
>
> dollars on hand, so no voltmeter, no breadboard, no
>
> spools of wire. I remember building the basic 556
>
> “Atari punk console” circuit and just thinking it made
>
> horrible noises nobody would ever want to hear.
>
>
> After building light-controlled oscillators for a
>
> year, I started checking out books at Colorado State
>
> University. The ancient books were the best: Musique
>
> Concrète and this book written in Spanish from the
>
> 1940s showing how a film loop generating optical
>
> pulses going into a modulator circuit could be what we
>
> call a drum machine. My mother told me about the
>
> Telharmonium in Worcester MA she read about in Yankee
>
> Magazine. I built a Theremin using an oscillator and
>
> an AM radio, and realized it would be easier to master
>
> the violin than to get a melody out of a Theremin.
>
> Then I found the 1970s books from UCLA on what we now
>
> call West Coast Synthesis. When I got to the log
>
> tables in the middle of the book I knew I couldn’t
>
> follow it; if music was math, music was not for me.
>
>
> It took a couple of years of futility to realize I had
>
> to try again.
>
>
> Paia was so inspirational, yet at the same time I felt
>
> the kits were full of design compromises that left me
>
> in the dark about best practices. (I remember testing
>
> the Gnome after my brother put it together and we both
>
> thought it was broken; but it was just the T filter
>
> doing its crappy T filter thing.)
>
>
> Then I was gifted a broken Paia Proteus when I was a
>
> junior in high school. Fixing that beautiful machine
>
> gave me a new appreciation for Paia.
>
>
>
>
>
> Paia turned me onto Don Lancaster and Craig Anderton
>
> (as editor of Electronic Musician).
>
>
> After I got my hands on the books by Bryce Ward and
>
> Barry Klein, I really wanted to do this stuff, but I
>
> had no way to earn a living, and neither the math nor
>
> the music.
>
>
>
>
>
> How long does one have to live before you just start
>
> doing what you love?
>
>
>
>
>
> Benjamin Tremblay
>
>
>
>
>
> > On Oct 9, 2020, at 6:53 PM, Benjamin Tremblay via
>
> Synth-diy <Synth-diy at synth-diy.org>
>
> wrote:
>
>
> >
>
>
> >
>
>
>
>
>
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