Quick question...I'm interested in picking up a cheap oscilloscope to investigate things like my busted Stepp DGX, see if I can see what pins are sending digital signals etc. I've noticed a Farnell DTV 40 40MHz dual beam scope locally; would that enable me to display signals from something like, I dunno, I2C for example? (I don't know a lot about electronics.)
*edit*
I just searched YouTube for I2C and oscilloscope and found a demo of someone reading the actual data. I had no idea oscilloscopes could do that. (That MDO3104 is £22K though.)
(I2C was invented years after the Stepp anyway, just an example. I've no idea what kind of analogue/ditigal communications would be used on '80s equipment like that. I'm starting to think that if I was going to look at oscilloscopes though, I'd probably be better off with some digital computer-based thing than an old analogue one.)
I don’t know the specs of that Farrell scope, but to analyse digital comms (or indeed anything other than a regular waveform, you’ll need a scope with a storage facility.
Quite good ones can be had for a couple of hundred pounds these days, and something capable of capturing the sort of signals you’ll probably be looking for probably quite a bit less if you’re prepared to risk Aliexpress.
Back in my day a decent Tectronix storage scope would be a significant 4 figure investment
I'm not familiar with the DTV40 and a quick Google didn't turn up anything useful, so I don't know what facilities it offers.
However, I have seen some real bargains going on marketplace recently, presumably selling after an hobby engineer has passed away.
Old analogue scopes take up space, though, and they will inevitably be old so reliability could be an issue.
When my last analogue 'scope died I replaced it with a Pico which is a scope interface that connects to the computer via USB and everything is controlled and displayed on the computer. They do a wide range of models at different prices and capabilities. I have a 3000 series model which is adequate for my simple needs and includes a useful signal generator. There are more elaborate and faster versions for involved digital work.
Technical Editor, Sound On Sound...
(But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!)
In my world, things get less strange when I read the manual...
Hugh Robjohns wrote: ↑Fri May 26, 2023 11:04 amWhen my last analogue 'scope died I replaced it with a Pico which is a scope interface that connects to the computer via USB and everything is controlled and displayed on the computer. They do a wide range of models at different prices and capabilities. I have a 3000 series model which is adequate for my simple needs and includes a useful signal generator. There are more elaborate and faster versions for involved digital work.
I have a Siglent SDS1202X-E scope as I do some electronic design. While at around £360 this may be out of your budget it is generally regarded as the best low end but professional quality scope. It is a 2 channel 200MHz unit with full digital storage and can also do Fourier analysis. There are some Rigol scopes which come in a bit cheaper and are quite popular but the Siglent scopes have significantly more powerful digital processing and sample depth capabilities.
It can also do some protocol analysis but I'm out at present so can't recall what they are but there's a full manual online.
If I was going to buy a scope now I would probably go for a Pico Scope. A normal scope just takes up so much space although I do like having real controls for everything.
I've used one of the £200 Rigols and I felt the screen was just too coarse to see any detail - although the week before I had been using a more expensive Agilent scope so maybe I was just expecting too much from the Rigol.
I2C has been around since 1982 according to Wikipedia which is more recent than I expected. It is one of those things that feels like it has been around forever.
I know this thread is about oscilloscopes, but the question is looking at digital signals with a 'scope, and which one to choose.
However, for digital signals, I use a USB based, logic analyser. You can buy cheap, effective ones, for occasional use. I also have a DSO which can display digital signals, but it wasn't cheap.
And to put the case for Rigol, I have an excellent Rigo RF spectrum analyser/tracking signal generator, that whilst not inexpensive, compares very well on test, with high-end models from other manufacturers. (Some of which may be made in the same factory......)
Nazard wrote: ↑Sat May 27, 2023 8:14 amHowever, for digital signals, I use a USB based, logic analyser. You can buy cheap, effective ones, for occasional use.
