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Resisted the inevitable for too long - scope purchase time. — Parallax Forums

Resisted the inevitable for too long - scope purchase time.

__red____red__ Posts: 470
edited 2014-04-17 22:09 in General Discussion
Greetings!

I've now had two of my supposedly digital-only designs fail due to analog noise / levels issues that my current analog scope is not accurate / functional enough to diagnose.

From everything that I've read the Rigol scopes seem to have a good reputation. Really I looking for the analog equivalent of my saleae.com logic analyzer.

As well as being able to watch the world go by live I'd also like to be able to store, navigate and zoom through triggered events.

Budget is hard to swing right but 400 is the initial swing, but if doubling that will mean I don't have to re visit the purchase for a significantly longer time I may be able to swing it.

I keep looking at many contradicting reviews on the subject of USB scopes like the Picoscope. Thoughts?


Red

Comments

  • Erik FriesenErik Friesen Posts: 1,071
    edited 2014-04-14 10:36
    What do you have now?
  • BeanBean Posts: 8,129
    edited 2014-04-14 10:42
    For the money it's hard to go wrong with the Rigol DS1102E

    Bean
  • Duane C. JohnsonDuane C. Johnson Posts: 955
    edited 2014-04-14 11:00
    Hi Red;
    __red__ wrote: »
    Budget is hard to swing right but 400 is the initial swing, but if doubling that will mean I don't have to re visit the purchase for a significantly longer time I may be able to swing it.
    I like the Rigols also.
    If the budget can swing it, 4 channels would always be my preference.
    DS1074Z at $585

    Duane J
  • __red____red__ Posts: 470
    edited 2014-04-14 12:02
    Erik Friesen wrote: »
    What do you have now?

    HP 1707B.

    It's on its last legs. Connecting to the 1V 1khz "calibration" source and after 10 or so minutes the wave becomes less square and more "half-wave rectified" and the amplitude varies by unpredictable amounts.

    I don't know which to distrust, the calibration osc or the scope itself. It also has **horriffic** astigmatism which is outside of the range of the astigmatism pot to fix.
  • __red____red__ Posts: 470
    edited 2014-04-14 12:06

    I filmed this last night analyzing the modulation of a chain of WS2812s direct from a propeller. You can see that it's hardly a square wav.
  • LeonLeon Posts: 7,620
    edited 2014-04-14 12:59
    I have a DS1104Z (100 MHz and 4 channels).
  • RDL2004RDL2004 Posts: 2,554
    edited 2014-04-14 13:00
    If $400 is a hard limit, then the DS1102E is about the best at that price, but it's pretty old and missing features found on more recent scopes. The newer DS1074Z and DS2072A add a lot of good stuff. such as intensity gradient displays, but prices are certainly higher. The DS2072A is very nice, but over $800. I would recommend you read some of the threads on the EEVBlog test equipment forum to get a better idea of what to look for and maybe watch Dave's video comparing the DS1052E and DS 2072.

    http://www.eevblog.com/forum/testgear/

    http://www.youtube.com/watch?v=_TSr9nFN1GU
  • mojorizingmojorizing Posts: 249
    edited 2014-04-14 14:57
    if you're happy with their product, https://www.saleae.com/ now offers analog feature to their Logic product line.

    Can't comment on those specifically - I have their Logic analyzer only, but I have the DS1102E which I'm happy with.
  • __red____red__ Posts: 470
    edited 2014-04-15 09:31
    I love my saleae but I can't wait 3 months. After watching the comparison video and reading other comparisons of the two generations I decided to get the DS2072A.

    Certainly more than I need right now but something I'll grow into.

    Thanks,



    Red
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-04-15 12:24
    I have looked at oscilloscopes locally in the past, but in Taiwan the brands are unknown to me. And now the shops don't even have a demo in stock, it is all catalog order.

    4 channels seems to be a lot. Haven't seen any 4 channel scopes here.
  • Too_Many_ToolsToo_Many_Tools Posts: 765
    edited 2014-04-16 22:28
    __red__ wrote: »
    Greetings!

    I've now had two of my supposedly digital-only designs fail due to analog noise / levels issues that my current analog scope is not accurate / functional enough to diagnose.

    From everything that I've read the Rigol scopes seem to have a good reputation. Really I looking for the analog equivalent of my saleae.com logic analyzer.

    As well as being able to watch the world go by live I'd also like to be able to store, navigate and zoom through triggered events.

    Budget is hard to swing right but 400 is the initial swing, but if doubling that will mean I don't have to re visit the purchase for a significantly longer time I may be able to swing it.

    I keep looking at many contradicting reviews on the subject of USB scopes like the Picoscope. Thoughts?


    Red

    For setting a budget, just consider how many hours you spent fixing the earlier problems...and what that time was actually worth.

    Bet it was worth more than $400.

    Have you considered renting a scope for a few weeks to finalize your design?
  • CuriousOneCuriousOne Posts: 931
    edited 2014-04-17 22:09
    Actually, PC based oscilloscopes aren't that bad, and they can offer significant budget savings. I have Hantek DSO 2090 - works just fine for already 4 years now.
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