USB / PC-based Osciloscope

[LaNeK779]

Hi all,

What is the general consensus on USB / PC-based osciloscopes? Is there a model that is worth it, positives/drawbacks, pitfalls?

I don't own a scope but I guess there has to be one in my arsenal for elementary use.
I just wouldn' t want to go all out and get a proper bench scope yet

so, any ideas, suggestions ?

thanks,
chris

[steve-o]

I dunno Chris, I've had a regular 'scope since the 80's so never needed a PC based one. Maybe someone else will chime in who has one

[logsquared]

I've been rocking with a CRT scope for 20 plus years myself. I have been wanting to upgrade to something with storage capability. The problem I see with the cheaper PC scopes is resolution. In fast switching circuits you might not see something you would on a CRT.

Too bad your not in the states I still have a few single trace scopes like the ones I gave away here on PL I while back.

[mixedgas]

For the last year as I traveled by air, I had to depend on the customer's scope, by company policy... Thus I got to try nearly everything LCD on the market. At many labs I requested they go borrow another scope. The reason being clunky input voltage ranges, inability to have a good external trigger, and low display resolution. You get what you pay for.

Eight bit OWON and INSTEK LCD scopes are owned by friends of mine who do not demand spike catching performance but want a decent hobby scope on a budget. They are "OK" for bench work. If you offered me one for lab work at the day job, I'd throw it at you. But only because of the low resolution and poor triggering at high speeds. However if I'm servicing a stereo or a laser projector, they are fine. For a home bench they are not that bad.

Picoscope was used by my former employer who wanted the Gold Standard machine in portable USB scopes with 10 bit inputs.

Make sure whatever you get has: two channels, separate external trigger input on a third BNC input, and XY plot mode. Memory depth and bit depth is very important. Being able to scroll back to "pre-trigger" or zoom without redoing the measurement is important. Both of those functions, if available, depend on memory depth. IF you really want something nice get a Tek DPO or a low end Lecroy... but those are starting at 700$. If 8 bit resolution is OK, and this is a home scope, get a 60 to 100 Mhz Owon or Instek... Avoid the 10, 20, and 40 Mhz USB scopes.

There are tonnes of USB scopes advertised out there, but precious few of them have a good external trigger circuit. It really sucks if you have to sacrifice one of your only two inputs for a simple TTL trigger.

I still own CRT based scopes for glitch catching, for a reason.

EEV blog and EEV forum has some low end scope reviews, but I'd watch what I see on Youtube, very, very, carefully.

Get the scope with the built in LCD, other then Picoscope, most USB scopes get limited by the USB transfer rate.

Steve

[LaNeK779]

Nice! That was really enlightening, thank you all!
Well, my bad for not giving out more info on the intended usage.

Servicing a stereo, laser projector work / dialing in a stray galvo is the intended use.

I don't have a problem with older used crt scopes, but not many can be found here.
Purchasing from ebay the shipping cost can climb quite a bit.

I' ve seen owon and rigol digital lcd scopes out there. At the moment their cheaper models are the ceiling of what I am searching.

[mixedgas]

Rigol probably beats Owon these days in quality.

Steve