How did kids in the old days learn without an oscilloscope? - Page 1
Forum section: electronics / beginners

author: SilverHawk
author_rank: Contributor
timestamp: October 06, 2016, 09:46:02 am
content: Hi there , i was wondering after listening to the interview with colin mitchell and his talking electronics magazines, about how kids used to learn electronics in the old days without oscilloscopes and if that is still applicable to this day, how much practical electronics can you really learn without an oscilloscope?Thanks

author: Audioguru
author_rank: Super Contributor
timestamp: October 06, 2016, 11:25:42 am
content: When I was a kid I learned about electronics in the old days 54 years ago without an oscilloscope and without the internet by reading about it in books and magazines. Then I designed simple circuits and built them but some did not work and I needed a multimeter and oscilloscope to fix them. So I built a kit multimeter and a kit oscilloscope. I still use the same oscilloscope today.Of course I learned about the details of electronics in university.

author: danadak
author_rank: Super Contributor
timestamp: October 06, 2016, 12:02:20 pm
content: A "starter" scope can be had if you have a PC.Here is a zero costs scope that might be of interest -If you need a scope, here is a PC based freebee that handles AC coupling only, but very usefull. Note in themanual you have to limit input to sound card on the order of a volt, but still application, with FFT and Sig Genmakes a very usable freebee instrument. Build an interface for the signal gen, a simple opamp buffer would do,to buffer sound card output, and an attenuator/clamp on sound card input and you should be good to go. Acouple diodes paralled should work as a clamp.https://www.zeitnitz.eu/scope_enhttp://www.daqarta.com/dw_0all.htmhttp://homediyelectronics.com/projects/howtomakeafreesoundcardpcoscilloscope/?p=3http://www.build-electronic-circuits.com/sound-card-oscilloscope/After you build the protective interface to sound card check it first by placing a higher Von input to protective circuit and look at output of circuit that would connect to soundcard input.Note this scope is only good for audio type frequencies.Regards, Dana.

author: nfmax
author_rank: Super Contributor
timestamp: October 06, 2016, 12:03:00 pm
content: When I were a lad, I had the use of a moving-coil multimeter and a soldering iron, and apart from batteries that was it. We used to make 'signal injectors' - basically a battery powered audio oscillator - and use a crystal eariece as a high-impedance signal detector. Learning from magazines and the odd book (but they were a bit pricey). I first came across an oscilloscope at school in a physics class; then my father took an OU course where they provided him with a 'generatorscope' CRO plus oscillator which I was very occasionally allowed to use. Only when I started university did I actually get full use of a scope - but only after passing the 'oscilloscope driving test'.And there weren't any PCs then, either!

author: Brumby
author_rank: Unknown
timestamp: October 06, 2016, 12:16:15 pm
content: An imagination is helpful and some creative alternatives like thisQuote from: nfmax on October 06, 2016, 12:03:00 pmFor those who learn through visualisation, the process is a little easier - especially if they have a feel for how individual components work.Getting an oscilloscope is like moving from a telescope trained on Mars to the Curiosity rover.

author: EEVblog
author_rank: Unknown
timestamp: October 06, 2016, 12:34:41 pm
content: I didn't get my first scope until I was maybe 14 or something (saved up my cash-a-can money), so that was a good 4-5 years without one. I started earlier, but didn't get really serious until maybe 9-10yo.You simply used a multimeter, a logic probe, a tone tracer etc.You candoa surprising amount without a scope, butdoingis not always the same as learning.

author: rstofer
author_rank: Super Contributor
timestamp: October 06, 2016, 02:31:12 pm
content: Maybe Popular Electronics magazine with their monthly projects was a help. I do recall that buying parts was problematic. Some of the TV repair shops would sell what components they carried like resistors, capacitors and vacuum tubes but anything else had to be ordered and that was done by mailing in a form with a check and hoping to see parts one day.Heathkits were popular, and I built several, while the ARRL Handbook was the ultimate reference. I suppose I could have tried the library but I never did.You can go a long way in electronics without a scope but I don't think you get the 'feel' for how things work if you can't see what's happening. The $400 and under scopes today are better than anything available back in the '50s. $400 isn't insignificant but it is a long term investment and if you get 10 years of service from such a unit, the cost is about $3 per month.I have had an oscilloscope since I built one from plans in the ARRL Handbook back in the late '50s. I really should research that project and try to nail down the date. It didn't have much for vertical amplifiers but it worked, more or less.So many projects today are based on microcontrollers (Arduino as an example) and while a scope is handy, it isn't absolutely required. You can struggle along and build some pretty amazing projects with minimal tools. Most of the project is software.Electronics is just one of many hobbies and I have dabbled at it for 60 years or so but, basically, I'm a code wienie. It's just lately that I am looking at analog circuitry. I blew that stuff off in college because the math was just too ugly to work with as a hobby. I truly struggled with Differential Equations in college while today I play with them on an analog computer just for giggles. How odd that damped harmonic motion is easy to model and it was the topic of the evening last night while I helped my grandson with his Pre-Calculus homework. Talk about tying things together! It's a matter of having the tools, I suppose...I have written several times recently about the virtues of the Digilent Analog Discovery (search the forum). For $279, the gadget includes 2 scope channels (limited to 25V), two arbitrary waveform generators, 16 bits of digital IO that can be used as a logic analyzer and some other tools. This device is literally a lab in a box. You can do an amazing amount of electronics with this gadget. The new version picks up the pace on the dual power supplies to where it now delivers over 2W per output. This is a great improvement over Version 1. So much so that I'll probably buy one even though I have V1.I'm not a fan of the sound card scopes primarily because I don't want to smoke my computer. If I did use one of these devices, it would be on an old junker. AC coupling is a limitation when working with digital circuits and, since digital is my interest, I just can't get excited about the concept.I think most people blow right past the Analog Discovery and don't spend the time it takes to realize just what the tool can do. There are a lot of YouTube Videos (including one by our host) and they seem pretty useful. Dave is right, the Network Analyzer tool (used to make Bode' plots of amplitude and phase angle versus frequency) is very useful for characterizing tuned circuits. While you're at the Digilent site, check out their LEARN page. That Real Analog: Circuits I program is very serious electronics. I remember those topics from way back when...

author: Alex Nikitin
author_rank: Super Contributor
timestamp: October 06, 2016, 02:56:56 pm
content: Books about electronics, several of them, mostly collection of data sheets about valves, transistors, passive components - you can learn a lot by reading these. A moving coil meter, a soldering iron. Then I've build my lab bit by bit - starting, when I was about 14, with a simple stabilized and protected 0-30V, 300mA power supply, next came a scope - there was no way at that time and place to buy a proper scope(the USSR, mid-1970th), so I've bought as a junk a very old valve scope (AC only, 250kHz bandwidth) , removed all circuitry from it, leaving only the CRT, the case and the mains transformer, and built a rather nice (single channel though) DC-10Mhz scope, using my own circuit design (I was 16 by then). After that a better dual rail power supply, a function generator and an AC millivoltmeter (1mV - 100V full scale, 5Hz-500kHz BW). I've used that equipment for next fifteen years to design and test hundreds of circuits.CheersAlex

author: setq
author_rank: Frequent Contributor
timestamp: October 06, 2016, 03:08:06 pm
content: A scope is a time domain instrument.There are three ways to get around not having one by leveraging that:1. Measure in the frequency domain as it's probably easier. You can peak amps, design filters without a scope. You just need an AC capable multimeter (mine was a moving coil Micronta piece of junk) and a signal source and frequency counter. The frequency counter is built into a UT-61E multimeter for me. Here's a signal source I hacked up yesterday out of some junk I had lying around to test a filter (yes that inductor is wound on a mcdonalds straw)http://imgur.com/a/EvXDb2. Slow everything down so you can measure it with a meter or an LED or something. Logic probe is the canonical example of this.3. Make some assumptions and test the effect of them, rather than observing them. For example, with audio you can listen to signals and get a rough idea of harmonics without a scope.I have a scope, but it doesn't really get used terribly often these days.Edit: also I have had lots of broken scopes. These force you to think around the problems of not having one.

author: zapta
author_rank: Super Contributor
timestamp: October 06, 2016, 04:31:34 pm
content: Quote from: SilverHawk on October 06, 2016, 09:46:02 amElectronics is much easier to learn these days, not because the availability of cheap oscilloscopes, but because the the availability of information and parts that the Internet brought. With a click of a button you can find any datasheet you want, ask people all over the world and order components in small quantities and reasonable prices, regardless if you live in a big city or a small rural town. IMO, this is the biggest change in the electronic hobby and learning scene.

author: Gyro
author_rank: Super Contributor
timestamp: October 06, 2016, 06:31:46 pm
content: It's really hard to overestimate how much the internet has changed things. When I started out you used to look forward to the days when one of the Reps was coming in with his box of 'goodies'. With any luck you'd scrounge your own set of databooks (Nat Semi were particularly generous) which you would immediately mark all over with your name so they didn't get stolen. If you needed a specific datasheet, you'd phone the distributor, persuade him that he should give you one for free and then wait for it in the post the next day. At a pinch you could get a partial faxed, but the resolution was lousy. For help with component selection you'd have to phone an app engineer or the distributor and hope that they were on the ball. You really needed to think ahead if you were going to make sensible progress.Even this level of support was only available to engineers, hobbiests had to glean things from the electronics magazines. You tend to forget unless you think back but it's a totally different world these days. In some ways, having (access to) a scope was the least of your problems, current information was.P.S. I still have my three successive treasured issues of the NS linear applications handbook, still useful today.

author: David Hess
author_rank: Super Contributor
timestamp: October 06, 2016, 09:22:34 pm
content: You learn to detect spurious oscillation by monitoring supply currents and operating points. If a precision circuit has mysterious level shifts with no apparent reason, then you might add small amounts of capacitance or resistance at various points to detect oscillation. Judicious application of the mark-1 fingertip can be used for this in some cases.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 06, 2016, 09:41:38 pm
content: Quote from: Gyro on October 06, 2016, 06:31:46 pmI had a complete wall of databooks, accumulated over many years. Also a pretty large collection of mags, mostly ETI and the occasional Wireless World and Elektor.Any one remember the huge and expensive IC Master books? These proported to list just about every IC by every manufacturer, though I don't recall them being hugely useful in practice.Another more useful publication was CIE's distributor directory, which listed distributors for every manufacturer and I think also had some product category listings. They published it every year at a fairly high price, but also sold off the previous year's editions much cheaper

author: David Hess
author_rank: Super Contributor
timestamp: October 06, 2016, 10:45:07 pm
content: Quote from: Gyro on October 06, 2016, 06:31:46 pmA visiting friend once incredulously exclaimed to me, "How did you get a McMaster Carr catalog?"For a while I lived close to the Motorola literature distribution center at Irvine Spectrum and they had no problem with my dropping by, signing it, and raiding their documentation inventory room for whatever I wanted. Little did they know I was a student at Cal Poly Pomona instead of the close by University of Irvine.Some companies were much more liberal about sending databooks and samples. I never had any problem with National and Maxim for instance but I had to inherit most of my Texas Instruments books. Linear Technology sent me everything except their application books which I had to buy. Unitrode and Analog Devices sent me their stuff but PMI did not.Quote from: mikeselectricstuff on October 06, 2016, 09:41:38 pmI still have my databooks if not immediately available then in storage boxes.QuoteI have two widely separated years of the D.A.T.A diode and transistor books.

author: Gyro
author_rank: Super Contributor
timestamp: October 07, 2016, 08:54:39 am
content: QuoteAh yes, another ritual, the 'inheriting' of the databooks. Whenever someone left the vultures would circle looking to pick off 'scraps' on their last day (hey, you still want that?). It all seemed good clean sport until it came to my turn (Buggeroff I'm keeping that!).I still have a few boxes full too, I would have more, but one weekend I sorted then into 'useful' and (smaller) 'less useful' piles in the garage. The next day my wife decided to take the wrong pile to the tip while I was at work.

author: CJay
author_rank: Super Contributor
timestamp: October 07, 2016, 11:08:50 am
content: Databooks, magazines and enthusiastic friends (many years after one friend passed away I found out he designed and had published several projects for electronics magazines) but I was relatively lucky in that my first full time job gave me access to an oscilloscope, sig gen, frequency counter and lots of other gadgets I could use to work on my own projects 'out of hours' as I had a key for the business.I haven't 'learned' electronics, I'm still learning.

author: setq
author_rank: Frequent Contributor
timestamp: October 07, 2016, 11:49:01 am
content: Quote from: Gyro on October 07, 2016, 08:54:39 amThis is why I do all the cleaning and tidying!

author: oldway
author_rank: Super Contributor
timestamp: October 07, 2016, 12:05:08 pm
content: I began to learn electronics at 13 years old in the valves era.I was buying all the electronics magazines I could find.Very soon I bought my first oscilloscope because I was aware that an oscilloscope is realy "the eyes" of the electronics technician.My first oscilloscope has been a Heathkit IO-12E.I had a lot of fun with it.I was building a lot of kits, the most often amplifiers, and my own valve amplifiers.Later, I worked with color TV repair and a good oscilloscope was essential because the signals were very complex.I used then Telequipment and Philips oscilloscopes.

author: nfmax
author_rank: Super Contributor
timestamp: October 07, 2016, 12:11:39 pm
content: Hands up if you are old enough to have used an oscilloscope with a 'stability' control!

author: setq
author_rank: Frequent Contributor
timestamp: October 07, 2016, 12:13:09 pm
content: Quote from: nfmax on October 07, 2016, 12:11:39 pmNot old enough but broke enough to only be able to afford one with that in the distant past!Now I spent £10 on a 50 MHz Philips PM3217 and I'm happy

author: eugenenine
author_rank: Frequent Contributor
timestamp: October 07, 2016, 12:34:20 pm
content: A lot of the 'projects' we built as kids didn't need one. How many of us got the Forest Mimms books from Radio Shack, the 555 timer, the 741 op amp. All of those 'projects' were in the audio frequency range.When I was a senior in high school an uncle gave me a Tek 212. it was later stolen and I was scopeless until this year when I found two different Tektronix 2200 series for $40 and $50 so now I use one and my son uses one.

author: Unknown
author_rank: Unknown
timestamp: October 07, 2016, 01:25:38 pm
content: Well the fundamentals are no different now than they were years ago, Ohms law is Ohms law. Like most I started with an analogue meter and a stack of mags / databooks. The lack of anything else made you get on and experiment and witness the glory of the magic smoke. If you needed test gear you either built it or applied lateral thinking to whatever you had. No 16 channel logic analyser? No problem, tune an AM radio to a clear spot and listen to your program. The biggest game changer of modern times is the internet, not cheap scopes. If you can't find what you are looking for on the web, you aren't looking hard enough.

author: zapta
author_rank: Super Contributor
timestamp: October 07, 2016, 01:36:34 pm
content: Quote from: Z80 on October 07, 2016, 01:25:38 pmAs a kid I also didn't care how long it took to build things, time was plentiful and cheap, so eficency didn't matter.

author: free_electron
author_rank: Super Contributor
timestamp: October 07, 2016, 02:26:45 pm
content: just because in the old days people learned electronics without an oscilloscope does not mean you shoul ddo that now. yes it can be done , but why deny yourself the insigt that the avaialble machinery can give you ?How did people get to work before there were cars ?how did people eat soup before there were spoons ?how did people stay warm before they developed the knowledge to make, maintain and transport fire ?

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2016, 02:40:49 pm
content: Quote from: SilverHawk on October 06, 2016, 09:46:02 amWe used thought, skill and imagination. (Also see my .sig) Another key is testing little bits in isolation, where each test isolates one facet of the equipment's behaviour.Themindsetis equally relevant today. Consider, for example:testing any equipment composed from many components, where a component can be of any scale - e.g. an individual transistor, or a complete PC, or a telecom billing systemhow you would test the world's fastest scope, or highest precision voltmeter

author: zapta
author_rank: Super Contributor
timestamp: October 07, 2016, 02:49:52 pm
content: Quote from: free_electron on October 07, 2016, 02:26:45 pmThat's a red herring. I don't think anybody objected for using spoons or oscilloscopes.

author: CraigHB
author_rank: Regular Contributor
timestamp: October 07, 2016, 02:57:40 pm
content: I started with electronics about ten years of age in 1970. I never even used a scope until I got into the electrical engineering school in college. There's a lot you can learn with only a multi-meter and a breadboard. For simple circuits that teach basic concepts a scope is not required. However once you get into projects that perform some useful task it's hard to get by without one. I used an analog scope for the longest time and finally got my first DSO a few years ago. Now I wonder how I got along without it. I think you just do the best you can with what you have. There's a number of test instruments I wish I had but don't due to cost. I manage to get by without them.

author: David Hess
author_rank: Super Contributor
timestamp: October 07, 2016, 03:14:32 pm
content: Quote from: nfmax on October 07, 2016, 12:11:39 pmI had one of those Heathkit oscilloscopes when I was like 12 but I did not really understand how to use it.Two hands up if you *still* have an oscilloscope with a stability control and have used it! (Tektronix 545)Quote from: eugenenine on October 07, 2016, 12:34:20 pmSO: Uh, whose oscilloscope is that in the living room?Me: Mine. Tektronix 2232. The oscilloscope I've always wanted and now I have it. I rule!

author: retrolefty
author_rank: Super Contributor
timestamp: October 07, 2016, 04:36:25 pm
content: Back then, as now, one can learn lots about electronics by starting in the DC domain. Just a simple multimeter can and does go a long way in learning and even building simple projects. After that a scope does help immensely in working in the AC/RF domain.

author: rstofer
author_rank: Super Contributor
timestamp: October 07, 2016, 05:19:03 pm
content: It wasn't until the very late '60s that it became possible for hobbyists to experiment with digital systems. I'm not sure when RTL was introduced to the hobbyist but I ran across it in 1969. Prior to that time, flops were built up from transistors and there was some kind of limit to the types of projects hobbyists could build. Perhaps a CPU was out of the question.Once we started playing with logic, the requirement for tools increased (in my view) in that a logic probe was a minimal requirement and a scope wasn't far behind. By '75 or so, microcomputers were becoming available at the hobby level and the speeds were so fast that a logic probe didn't provide much information. Sure, a signal blipped but when? About '79 or so, I built a floppy disk controller for my Altair 8800 using a Western Digital 1771 controller chip. That project REQUIRED a scope! And, in my view, digital projects have ever since.Some time around '75, I built a Pong game from the original logic diagrams. That project used 66 integrated circuits (more or less) and the wire-wrapping was considerable. I think I got by with an old Dumont scope and a logic probe. I'd have to wait 41 years to get my first DSO...http://hackaday.com/2012/12/22/fabricating-hardware-from-the-original-arcade-pong-schematics/Heathkit projects could be built without test equipment and, where testing was required, the device itself became the test equipment. I think that was the case for the color television kit. I never built one. I just built an audio amplifier (late '50s) and the power supply, VTVM and VOM in the late '60s.

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2016, 05:38:31 pm
content: Quote from: rstofer on October 07, 2016, 05:19:03 pmTell me about itI built a multivibrator 7-bit counter out of transistors, resistors and capacitors that I had liberated from random sources. It worked, and swiched my radio off after the relevant number of minutes.Quotein '76 I built a 6800 (inspired by the Altair 8080) with 128 bytes of RAM without a scope. The PCB construction technique was primitive (sticky-backed plastic used as etch resist!), but it worked. It was very successful in helping me get my first job.I concur w.r.t. logic probes; they tell a signal changed, but so can ananaloguemultimeterQuoteFor checking signal integrity, yes. For checking embedded system program function printf() and LEDs arestillvery useful, and a multimeter can be used to determine things such as mean spare time in a processing loop.QuoteI built a glass TTY display controller using wirewrap, without a scope.QuoteGood example.

author: rstofer
author_rank: Super Contributor
timestamp: October 07, 2016, 06:11:36 pm
content: Quote from: tggzzz on October 07, 2016, 05:38:31 pmI use printf() {or equivalent} all the time. The first thing I do on any microcontroller project is get the UART running. Toss in a couple of binary to hex display functions and I'm pretty much good to go.LEDs are useful as long as they are on long enough to see and at least one of my multimeters does %on time. It's a matter of knowing what you have and knowing how to use it.I have only had my DS1054Z for a few weeks but it makes all previous techniques obsolete (well, printf() is still useful). Things are so much easier with a modern scope! And I do know how I got along without it!

author: med6753
author_rank: Super Contributor
timestamp: October 07, 2016, 06:12:11 pm
content: I was lucky. Before my Father joined IBM in 1955 he owned a TV repair shop. When I expressed an interest in electronics about 1965 or so he got the Heathkit O-10 scope and V-5 VTVM out of storage and fixed them up. So I had a scope right from the get go and no idea how to use it. But I soon learned.I still have the Heath V-5 VTVM but the scope went to my younger brother.

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2016, 06:41:37 pm
content: Quote from: rstofer on October 07, 2016, 06:11:36 pmJust so.My principal (and principle) objection is to people that think (and worse claim) that you absolutelymusthave the latest and greatest of everything.

author: tggzzz
author_rank: Super Contributor
timestamp: October 07, 2016, 06:52:49 pm
content: Quote from: blueskull on October 07, 2016, 06:40:46 pmBack in 1981, I reused the compiler's printf() by replacing the putc() with something useful on that machine. Since it was an embedded Z80, the application didn't use floating point and it wasn't in the binary. I don't recall changing the printf() function, so I don't remember how the "%f" was omitted.QuoteGeneric profilers have their places, but in shipping systems I've used custom performance profiling techniques to get other companies in trouble ("Here's what I sent you, and you tookthislong to reply; that's out of spec").

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 07, 2016, 07:42:23 pm
content: Quote from: free_electron on October 07, 2016, 02:26:45 pmThere is merit in learning to crawl before learning to walk, and to walk before learning to run. An oscilloscope is a wonderful tool, but unless you understand why those wiggly lines are doing what they are doing it is useless. Depending on your level of knowledge and skill the lines on the scope may represent some aspect of the real world, or they may be totally bogus garbage. Even when the lines are an accurate representation of reality there is plenty of misdirection possible. Is that noise an artifact of the measurement system (a real thing, but often not relevant to what you are trying to do) or is it actually coming from your circuit? Once all that is sorted out, what do you do with what is left.Some folks can learn very well looking at the wiggly lines. Other brains are constructed differently. And some don't realize they don't know everything. It is sometimes hard for those who have mastered a subject to understand the confusion and pitfalls for the beginner. One advantage of learning without an oscilloscope (at least initially) is that it usually forces you to take smaller bites out of the problems.

author: rstofer
author_rank: Super Contributor
timestamp: October 07, 2016, 07:48:51 pm
content: And then there is the CP/M incantation of DEBUG. I remember many wasted hours single-stepping through somebody else's code. What a colossal waste of time!Core dumps are another nightmare especially if the underlying CPU lacked a stack and self-modifying code was 'normal'. The IBM 1130 comes to mind...How about single-stepping an FPGA CPU? It was easier with a 32 bit logic analyzer. Since Digilent has gone all-in on PMOD connectors and eliminated the large headers, this has been getting more difficult. One thing a 32 bit analyzer does is make you wish for a 64 bit analyzer. This is particularly true if the FSA is using one-hot encoding. It takes a fair number of bits to figure out what state you're in!Regrettably, printf() doesn't work well for FPGA projects. Or it's just a whole lot more difficult!

author: rstofer
author_rank: Super Contributor
timestamp: October 07, 2016, 08:46:52 pm
content: Quote from: blueskull on October 07, 2016, 02:38:21 pmMoney is always an issue! I kind of like the Maker movement where tools and facilities are shared among the members.I also agree that you can get along without one and, if forced, that can go on forever. There's always a way!There's a lot of electronics manufacturing in Malaysia, there must be a market for used test equipment. Singapore is another hub of electronics manufacturing with lots of small companies.

author: eugenenine
author_rank: Frequent Contributor
timestamp: October 07, 2016, 08:53:19 pm
content: Quote from: David Hess on October 07, 2016, 03:14:32 pm"his" scope is in the dining room. I was going to sell the one when I got the better one but it seems its been claimed.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 07, 2016, 09:35:23 pm
content: Quote from: rstofer on October 07, 2016, 07:48:51 pmNice thing about FPGAs is you can build whatever test gear you need right on the chip!

author: coppice
author_rank: Super Contributor
timestamp: October 07, 2016, 09:58:22 pm
content: Quote from: mikeselectricstuff on October 07, 2016, 09:35:23 pmWhen you are trying to monitor something that's going on deep inside a chip, you really don't have any choice.

author: rstofer
author_rank: Super Contributor
timestamp: October 07, 2016, 10:15:05 pm
content: Quote from: mikeselectricstuff on October 07, 2016, 09:35:23 pmTo some extent that is true. The problem with trying to stuff a logic analyzer inside my CPU project was that I had already used up all of the BlockRAM. I did set output flags that would indicate where I was in the FSA because encoding or decoding the state was a PITA. I also carried 32 bits of Debug bus through most of the logic modules. I just commented it out when I was done with a module.The Integrated Logic Analyzer implemented in the Xilinx Vivado toolchain is another nice improvement. I have only done a couple of demo projects with it but I look forward to using it for real some day soon.I guess if it got down to sound card or nothing, I might reconsider my opposition. It's better than nothing even if it is severely bandwidth limited, only AC coupled and poses some risk to the PC. I suspect that a lot of people have junk PCs around and almost anything will be able to keep up with a sound card.There isn't a lot of difference between a sampling scope and a logic analyzer. Given that, I might take an FPGA and a ADC and build up some kind of scope. Or maybe I would just use one of the ARM processors. I could probably sample at multiple MHz so the bandwidth might not be too limiting. There are a number of these projects on the Internet.Maybe it's too much work and the sound card takes on a new appeal.

author: eugenenine
author_rank: Frequent Contributor
timestamp: October 07, 2016, 10:23:34 pm
content: So if t your using an FPGA to make some test equipment and you make some test equipment inside the fpga that your using to make your test equipment in the first place is that sort of like when you use a vacuum to vacuum your vacuum and it implodes inside itsself?

author: vk6zgo
author_rank: Super Contributor
timestamp: October 07, 2016, 11:39:03 pm
content: Quote from: blueskull on October 06, 2016, 12:03:34 pmNot particularly uncommon---If 'scopes are for home use,they aren't left on 24/7 like many used in commercial service ,so the filament hours are reduced radically.There is really nothing to go wrong with the phosphor,apart from "burn-in",& again that is unlikely in home use.A lot of old gear has had the electrolytics & a few other parts changed throughout the years,but they are still substantially the same instrument.

author: Howardlong
author_rank: Super Contributor
timestamp: October 08, 2016, 12:09:30 am
content: As others have suggested, you can work out a hell of a lot with a moving coil multimeter, even a crappy 1k ohm per volt like I had. Supplement that with an LED and resistor, and you can debug a lot of digital stuff. Add a monostable to catch pulses (logic probe). We did a lot of make do and mend back in the 70s as teenagers.With RF we used wavemeters with different coils for HF and very low VHF. For higher frequencies it was "tuning for maximum smoke".I didn't get my own scope until I was in my mid 20s, although I'd begged and borrowed on the infrequent opportunities that turned up. Having very occasional access to a delayed timebase scope was a real eyeopener, but learning how to configure the CRO's dual timebase up properly I remember was a steep learning curve as a teenager. Even now I have to think a bit to get some of the more esoteric delayed timebase modes of a 2465B to work when I get it out, and that was my main daily driver scope for some years.In real terms the cost of a decent scope has never been lower, but equally I'm also sure the functionality of scopes isn't even touched by their owners.

author: vk6zgo
author_rank: Super Contributor
timestamp: October 08, 2016, 12:17:45 am
content: Kids built projects out of magazines,The better ones like "Radio Television & Hobbies" (formerly "Radio & Hobbies".later "Electronics Australia") gave circuit operation descriptions.RTV & H also had a lot of basic theory articles.We also voraciously read books --ARRL Handbooks,RSGB Manuals,& so on.Some authors of Electronics books had great names,like Fink,Chinn,Scroggie & other whimsical sounding monikers.There was usually a older friend or relative into such things who would loan,or gift older versions.We made Radios---- hobbyists commonly had a better understanding of Superheterodyne principles than some folks asking (& answering) questions on this forum.Audio amplifiers were also common projects,back when HIFI was a "Geek" hobby.Many people of that period had the ability to "visualise" the operation of circuitry---an ability which seems far less evident these days.Electronics was BIG--enthusiasts usually found ,if not Apprenticeships,counrter & store jobs with local Electronics shops.To increase their knowledge,many attended Technical College night school classes.My first "hands-on" experience with an Oscilloscope was at around 13 when my brother brought a little 2" AWA 'scope home from work.It was fascinating injecting random mains hum into the vertical input & watching the "wiggly lines".Next time was at Perth Tech School,where they had Cossor 'scopes.When I got a real Technical job (at 22),I was amazed by the wondrous Tek 545 & similar,but didn't get to play with them.That job fell through,& in the next we had 5" AWA & EMI 'scopes,with fairly poor bandwidth,& a 5MHZ Serviscope.We hardly ever used them.Then I was sent to a TV Transmitter site with a 545B which was used regularly.What a nightmare learning how to use the Delayed timebase !My first private 'scope was when I was about 29----just a collectors item,really,as it was a 2" Philips which looked almost identical to that little AWA of so many years before.My firstreally useableprivate 'scope was a BWD which I bought secondhand in the late 1980s.

author: electrolust
author_rank: Unknown
timestamp: October 08, 2016, 12:51:36 am
content: I came up after punch cards, but I learnt computer programming literally with pen and paper. Whenever I could get at the actual computer I'd have to key everything in and see if it worked. When you're young you have the luxury of time on your hands so it's doable.It's not the same as "before the scope even existed" but the method is similar. You start at first principles and take your time, work out the math, etc. Not like we can do today which is just to be lazy on the basics, cobble something together and let the tools tell us where to go next.

author: Audioguru
author_rank: Super Contributor
timestamp: October 08, 2016, 01:23:25 am
content: Quote from: rstofer on October 07, 2016, 08:46:52 pmWhen I was a kid money grew on trees and was everywhere. Today there is also a lot of money around but I can't reach most of it.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 08, 2016, 03:06:13 am
content: I was given my first oscilloscope when I was too young. It was an old Dumont 100KHz tube unit. I experimented more with my first VTVM than I did the scope because I had some idea how to read the meter. I had made up some sort of light bulb brightness control that was sensitive to sound. Louder would make it brighter and I could sort of get that but that squiggly line just didn't make sense to me. I was playing around some with digital gates and had a little probe with LEDs in it that I used rather than the scope.Later I bought a booklet from Radio shack (which I still have) that showed how to use the scope.I bet those $20 kits would far exceed what I started with!

author: ebclr
author_rank: Super Contributor
timestamp: October 09, 2016, 06:06:11 am
content: We have oscilloscope in the old days

author: G7PSK
author_rank: Super Contributor
timestamp: October 09, 2016, 09:17:43 am
content: Electronic were invented or discovered when oscilloscopes had not even been dreamt of.People used the best tool in the universe, yes that one right between your ears. Worked fine for centuries, now I am not saying a bit of help and nice toys are no good but they are not essential to start with.

author: med6753
author_rank: Super Contributor
timestamp: October 09, 2016, 11:00:08 am
content: Quote from: ebclr on October 09, 2016, 06:06:11 amThat's the exact same one I had.....minus the colored inserts in the knobs and the additional BNC modification.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 09, 2016, 02:15:54 pm
content: I guess it goes hand in hand with what electronics and information access was back then. I grew up in the '80s (also the old days), but we had a set of youth encyclopedias from the '50s (even older days) lying around.It was the Encyclopédie de la Jeunesse Grolier.Each volume had some sort of practical project along the lines of arts and crafts, or something like a theodolite or periscope. I guess letting kids play with shards of mirror glass and wire didn't trigger a child protective services SWAT team in the old days.Anyways, the electronics projects were all about radio. They would teach about inductors (which in french are called "selfs", which made clear the distinction between self and mutual inductance at an early age) and variable capacitors and triodes. Eventually you'd wind a coil, buy a capacitor and some headphones and build a radio.That's the thing, when in a house the most electronics you had was a radio, a record player, and if you had money a TV, electronics was simple. Just having an explanation of what the parts looked like and did, how they were used together was already a lot. Money-wise a scope wasn't happening either, let alone how a parent would get one in the first place.

author: rstofer
author_rank: Super Contributor
timestamp: October 09, 2016, 03:46:34 pm
content: Quote from: G7PSK on October 09, 2016, 09:17:43 amYou can make the same argument about indoor plumbing and electric lights. Things come along when they do and there is always a way. But that's also the reason that growth curves tend to be exponential. There are limitations in the early days that are overcome and the growth rate increases. For example the microcomputer (PC)...The point is, you can learn faster if you have the tools to learn. Different people learn in different ways and tools can vary. Some people 'get it' by reading about it in a book. Some people 'get it' by building a model and playing with it. Simulation is better than nothing. How do you explain singularities like, for example, Einstein. He was so far ahead of everyone else on the planet, I wonder if he was really from 'around here'.Education is not free despite attempts to lower costs. In car racing, 'speed costs, how fast do you want to go?' is a popular truism. It's pretty much the same with education. Nobody would even consider doing all their work at a library when they can just boot up a PC and connect to the Internet. But PCs and network connections cost money and they are not universal. Many attempts are being made to bring those tools to every child in the US. They have not been successful. Yet...I would always advocate for having the proper tools but there a lot of electronics can be done with just a DMM and a V-O-M. It probably takes longer to digest the information but there are so many tutorials on the Internet that it should still be possible to go a long ways with electronics.

author: CraigHB
author_rank: Regular Contributor
timestamp: October 09, 2016, 04:16:37 pm
content: Quote from: Alex Eisenhut on October 09, 2016, 02:15:54 pmThe internet has made being an electronics hobbyist much more accessible. When I first started with this stuff it was all about the books I could get and parts I could buy from the local electronics shop. Online suppliers offering cheap parts and the wide availability of technical data and tools on the web has made a night and day difference.

author: tggzzz
author_rank: Super Contributor
timestamp: October 09, 2016, 04:54:55 pm
content: Quote from: Alex Eisenhut on October 09, 2016, 02:15:54 pmPah! Snowflakes.I have a couple of "Boy Electrician" books from the 30s, which have chapters on building and using X-ray machines. You had to buy the tube, and they did warn you that if your skin reddened you wereprobablyusing it too much.And of course there is the "radioactive boy scout" (David Hahn) in the 90s.

author: zapta
author_rank: Super Contributor
timestamp: October 09, 2016, 06:20:57 pm
content: Quote from: tggzzz on October 09, 2016, 04:54:55 pmLet me guess, he didn't survive to the 00s.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 11, 2016, 01:35:41 am
content: Quote from: zapta on October 09, 2016, 06:20:57 pmA little googling shows that he hasn't learned yet, but has survived so far. There are some obvious signs that his health has been affected.

author: rdl
author_rank: Super Contributor
timestamp: October 11, 2016, 02:25:50 pm
content: Apparently he died just a couple of weeks ago.http://www.tributes.com/obituary/show/David-Charles-Hahn-103989982https://en.wikipedia.org/wiki/David_Hahn

author: Syntax_Error
author_rank: Regular Contributor
timestamp: October 13, 2016, 02:07:27 am
content: Alright, so I admit I read the first five posts then skimmed the rest of this thread, so if this has already been said, I apologize.Although I do have a hobby oscilloscope, and love using it, to be honest at least 90% of the measurements I make with it are very basic, and could be handled by simpler equipment such as a frequency counter, power meter or peak detector.I mean, think about it. The majority of (steady state) signals are going to be known to some degree, i.e. not completely random and unknown in characteristics. How do you characterize an *ideal* pure signal? By it's frequency and amplitude, and as a distant third, by it's phase offset from some reference signal of equal frequency, if this is relevant to the situation.How do you characterize real (non-ideal) signals? With the same parameters, plus various measures of their "non-idealness" such as phase noise, spurs, % modulation, frequency deviation, etc. depending on the signal type and circumstance. While a spectrum analyzer may help tremendously in this type of characterization (and I'd love to have one myself), many of these measurements can be made with simpler equipment and some knowledge of the nature of your signal and system under test.Honestly, while I love making measurements on my scope, I often don't really need to see a time domain image of the signal, more just use the scope for measuring various properties of the signal of interest, such as period or frequency, amplitude, number of cycles in a burst, DC offset, etc. Of course there's many things a modern scope is useful for, such as rise time measurements and close inspection of pulses and things of that nature, but the *majority* of signal viewing (for me) is just a side effect of trying to measure the basic properties.