[Closed] Electronics peeps - which Oscilloscope?

can't really help but what computers have you got & what are you trying to revive at the moment? Used to be well into scouring boot fairs/ebay for old kit but not bought anything for many years as didn't have the time or any more room!! still got loads of stuff boxed up in storage though (cannot remember now which ones are non-working though!)

Pride and joy is a new boxed old stock A1200 with original Blizzard accelerator, got a boxed Dragon 32 as well!

I’ve got ZX81s that are in need of love, most of the Sinclair range but looking for a ZX80 in good nick. Also have a selection of battery portables from Tandy, Atari, Amstrad etc.. Now onto Commodores with a Vic20 that joined the stable today. It’s addictive! Let me know if you want to sell any.

Can't help you on the 'scope Dave, but - until about a year ago - I had an Acorn Atom and an Electron in the loft. No idea if they still worked, but would have been fun finding out. Unfortuantly we had a roof leak and they got binned along with a lot of other old stuff.

I've got my eye on an Electron

I’ve got my eye on an Electron

Underrated machine. We couldn't afford a BBC Micro and - back in the day - it was a bit tribal Sinclair V Beeb. So the Electron was nearly as as good as a BBC Micro and way cooler than a Speccy. Well that's what our side said 😉

I really wanted an amiga. I still kind of do, but it'd be a bit don't meet your heroes kind of thing. In the same way Sensible Soccer on the Vic20 can't be ANYWHERE near as brilliant as I remember it.

Anyway, wandered off the point there. As you were 🙂

I’ve got ZX81s that are in need of love, most of the Sinclair range but looking for a ZX80 in good nick. Also have a selection of battery portables from Tandy, Atari, Amstrad etc.. Now onto Commodores with a Vic20 that joined the stable today. It’s addictive! Let me know if you want to sell any.

cool... never got into 8 bit speccys/commodore as they competed with (and were vastly inferior to 😉) my beloved CPCs 😃 Having said that I do have a couple of different case design C64s that I acquired & don't think I've even ever booted up, and I might try to pick up a C16 or +4 at some point as the C16 was my first ever computer when I was 4 or 5!

Don't have an Electron but I have got an Acorn Archimedes A3010 (I think? sure it's the one with the green keys!!) I'm probably never going to do anything with. I'll have a dig around in the loft at some point and send you a list!!

I really wanted an amiga.

me too! Now I have 5 I think 🤣 They are still cool machines though, some of the games still stand up & there's definitely something about the real hardware as opposed to emulators, plus if you've got the time & inclination there's all sorts of modern bits you can fit to them now.

I used to use on of the little pocket DSO203 scopes as an emergency backup for work and it was pretty good for £120 - think it's now been superceded by the DSO213 for about £20-30 more. Should be more than accurate enough for what you're looking for.

If you want full-size then search eBay for the Tektronix TDS digital range; if you can get one of the EDU versions even better as they're the educational ones, so have simplified controls and inbuilt guides on how to use them, whereas the little pocket ones aren't very intuitive tbh.

A friend of mine is into that sort of thing and uses a rigol 1054z which is a bit over £300. He blogs about his retro computer stuff and I'm sure would be happy to chat about it: https://www.richardloxley.com/retro-computing/

I have a 100mzh hantec and that's fine for my usage. ITs always going to depend on the frequency of clock you are dealing with and if you want to record how long / deep. Also might be worth looking a logic analysers. Proper posh ones are mega bucks but there are a few hobbyist ones (dangerous prototypes et al) which I was looking at (again for similar hobby / slow digital) that may be of use. Never bought a LA but was next on my list of tool but then my work changed.

E.g. http://dangerousprototypes.com/docs/Open_Bench_Logic_Sniffer

I think there are better options available and by no means is this prolevel equipment but useful tool for old digital circets.

me too! Now I have 5

Loving your work there 🙂 Archimedes was the first ever RISC processor I think?

Archimedes was the first ever RISC processor I think?

I believe so, although mine is one of the last ones. Popular in schools apparently (mine is stamped with a schools details!) although never met anyone who actually remembers using one!

I did my maths degree on an Archimedes. Breaking news. The Vic 20 has fired up into life after some resoldering

The Vic 20 has fired up

Get Sensible Soccer loaded up!

I use this one https://www.amazon.co.uk/gp/product/B00I5EWF1U/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 although I only paid £220 for it!

Got it to replace my HP/Agilent 100Mhz scope that was just too huge for my desk!

Looks wise, I still love the old Commodore PET computers that some colleges etc had. If you think of a classic "personal computer design" this is the one that pops into your head.

I’d like a Pet but the computer I really want is a Jupiter Ace. I wanted one as a lad but had to make do with a Spectrum.

Not 'real' oscilloscopes, but then none are now as they're all digital based but I've used Picoscopes in the past and they are a reasonable compromise plug in for a PC though not as 'real' as a proper scope they can be easier to use than some of the newer ones with too many features for the occasional user to get lost in.
Old school analogue scopes are the easiest to use IMO but probably won't go fast enough for working out PC issues.

Some suggestions from me

1) don't bother with the chinese little pocket scopes. They are too fiddly, the screen is too small, and often the firmware is terrible and they can even show incorrect readings (due to things like aliasing and sampling errors). They seem cheap, but they are frankly, rubbish. Avoid!

2) If you are going to be doing "digital" debugging, then a logic analyser, which shows just a change in a signal, ie a digital edge is probably going to be useful. Salea do some cheap USB logic probes with lots of channels. These obviously cannot "see" an analogue signal, they are NOT an osciloscope, they simply tell you when in TIME a digital signal changed state.

3) A proper bench top scope is really not that expensive these days, and there are three options

a) an old CRT scope of a good manufacturer, probably 4 channels, but no storage and likely to be huge andpossibly fragile, but something like £100 gets you a good one. If got an old Tektronix 2245A on ebay at the moment that was my old backup scope

b) a low end modern LCD storage scope. Rigol own the market here for low end stuff, and the 1054 or similar have become the go-too starter scope. Although i have a nice £7k Agilent scope for my work, i often find myself using my 1054 instead because it's cheap enough that if it gets dropped or damaged i'm not too worried! If you need to debug things that happen over time, ie randomly, then a scope with a deep memory, ie lots of storage is key!

c) a USB scope, using your pc as the "screen". This brings the cost down, and is fine for ocasional use, but if you are going to use it a lot, a proper bench top scope, that is always there, needs no pc/windows to work must not be underestimated. Pico own this market, with a range of different options

In all cases, please watch this, and understand what it means, as it is CRITICAL to staying safe when working on mains powered devices

Also, lots of possible confusion around Sampling rate and Analogue Bandwith!

Sampling rate, in samples per second is simply how many times the scope can read an input. For a multichannel scope, especially the cheaper ones, that rate is most likely SHARED across all the physcial input channels. So a 4 channel scope with 1 millon samples per second can only read each channel at 250ksps when all four channels are being used.

Analogue Bandwidth, is the frequency at which an AC analogue signal is attenuated by some amount, usually 3dB. So a scope with a 100 MHz 3dB analogue bandwidth will show a 100Mhz sinewave as having half its true magnitude

Mr Nyquist mathematically proved that you only need 2 samples per integer waveform, although as that was for a sine wave, ie a fixed shape, that knowing two points on it, you could calculate the frequency and magnitude of that wave.

In reality, because you DON'T know what the waveform looks like before you measure it, mostly i'd suggest that you need the sampling rate to be at least at a 10 times higher frequency than the frequency of the highest harmonic of the signal of interest.

If you take the Rigol 1054Z for example, you'll find it has 50 MHz analogue bandwidth per channel, but samples at 1GHz (1000 MHz) in order to be able to define enough points on each waveform as to be able to show a reasonable approximation of that waveform.

IME, unless you are doing Radio, Radar, Wifi or similar, you really don't need that fast a scope. A 50Mhz scope will still show a 100MHz signal, it just will be heavily attenuated and the edges will not be sharp, but for fault finding and debugging, you mostly need to only know if the signal is there or not! IN conjunction with a logic analyser, that is very fast (because it doesn't bother trying to work out what the shape of the signal is, just is it considered logic low or logic high) you can almost certainly fix most things!

i'd generally trade bandwidth for more channels and more memory depth. The big advantage of the USB style scopes is that at lowish sampling rates (where the USB data link is not a constriction) they effectively have an infinite memory depth because the typical modern PC/Laptop has a HUGE harddrive!

Thanks @maxtorque really helpful