scope opinions - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: January 04, 2022, 10:49:21 pm
content: I just wondered if anyone has used one of these,if so are they any good?https://www.ebay.co.uk/itm/403051470988?hash=item5dd7bd608c:g:ZzgAAOSwmJxhDlXz

author: ledtester
author_rank: Super Contributor
timestamp: January 05, 2022, 01:17:12 am
content: 52 page and counting thread here:https://www.eevblog.com/forum/testgear/fnirsi-1013d-100mhz-tablet-oscilloscope/User pcprogrammer is actively reverse engineering and re-implementing the firmware. Still a long ways to go but the effort has uncovered some interesting shortcomings of the hardware design.

author: rstofer
author_rank: Super Contributor
timestamp: January 05, 2022, 04:02:39 pm
content: Pay attention to the "Maximum test voltage" - 40V with X1 probesFor that price, how good do you expect it to be? It certainly isn't a Rigol, Siglent or any of the other name brands but it very well could be 'good enough'.What do you plan to do with it? For audio, it is clearly good enough, for FPGA work the bandwidth is too low but that's the case for almost all entry level (<= 500 MHz) scopes.It is certainly better than no scope and could fill in the gap until funds are available for a much more capable scope.ETA: I watched Dave's video and this thing is really a 20 MHz scope. So what? That is fast enough for all Arduino projects and likely all RPi projects. There's an unrealistic idea that we NEED 100+ MHz. I got by with a 10 MHz Heathkit all through the early 8085, Z80 years including building my own floppy controller based on the Western Digital FD1771 controller chip. At most, those were 6 MHz signals and I somehow managed to get things to work.I could certainly see hanging one of these on my analog computer. The signals swing between +-10V and only at about 10 Hz I could permanently mount it and leave my bench scope alone. Dave didn't demonstrate X-Y mode and that is sometimes necessary. The scope has that mode.There are a lot of applications for this kind of tool.

author: tunk
author_rank: Super Contributor
timestamp: January 05, 2022, 05:45:44 pm
content: The minimum vertical setting is 50mV/div (and that's insoftware, 100mV in hardware). With a 10x probe that's0.5V/div or 1V/div.

author: Gyro
author_rank: Super Contributor
timestamp: January 05, 2022, 05:47:34 pm
content: Those things are deaf as a post aren't they? 100mV/div (ie. 1V/div with a x10 probe) with token 50mV/div done by doubling the image size in S/W.Edit: Snap!

author: rstofer
author_rank: Super Contributor
timestamp: January 05, 2022, 08:04:09 pm
content: Quote from: tunk on January 05, 2022, 05:45:44 pmWhich would leave a 3.3V logic signal displaying over 3.3 divisions with the higher bandwidth 10X probe. Add a second signal and a little spacing and the screen if pretty much full.Yes, a lower value would be much better but for logic, at least, it's not an issue, in my view.Perhaps most analog work could be accomplished with the 1X bandwidth. At least in terms of audio.

author: m3vuv
author_rank: Super Contributor
timestamp: January 06, 2022, 05:34:42 am
content: after seeing the vid,i must say it looks pretty crap,could see it beeing a good base for a homebrew tracker type component tester tho,thats assuming the xy mode works,would work out less than even a seconhand huntron tracker,homebrew with a few components and a small transformer.

author: tautech
author_rank: Super Contributor
timestamp: January 07, 2022, 03:26:14 am
content: Quote from: tunk on January 05, 2022, 05:45:44 pmLet's look at it the other way, 50mV/div max sensitivity and you need probe a power rail to check ripple which has a max 10mV p-p ripple spec.Totally useless for such simple and basic needs.