EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Kappes Buur on March 11, 2014, 12:57:21 am
-
Circuit Cellar (http://circuitcellar.com/cc-blog/evaluating-oscilloscopes-part-1/) ran a nice 4 part series about Evaluating Oscilloscopes.
-
:palm: The author bought a USB scope and made a USB keyboard emulator with rotary encoders to control it! :palm:
More nonsense:
If you end up needing DC 50 termination, you can buy “feed-through” terminators for about $15, which operate at up to 1-GHz bandwidth. You simply add those to the front of your oscilloscope to get 50-? terminated inputs. :scared:
The author also doesn't get that the 16 bit 'resolution' is coming from oversampling an 8 bit ADC. That is a bit optimistic to say the least. All in all it's a Picoscope advertorial. Nothing more.
-
:palm: The author bought a USB scope and made a USB keyboard emulator with rotary encoders to control it! :palm:
Oh wow, that's funny.
The second is I find it easier to interact with a standard keyboard and mouse, especially if you’re using more advanced features.
Then goes and builds that knob box:
(http://circuitcellar.com/wp-content/uploads/2014/02/Figure-2-for-web.jpg)
-
What could possibly go wrong? (https://www.eevblog.com/forum/Smileys/default/shocked.gif)
(http://imageshack.com/a/img691/5600/iu6e.png)
-
All in all it's a Picoscope advertorial. Nothing more.
Well, I think it does cover some basics, and scope choices, that go beyond Picoscopes. It could be useful and educational reading for newbies, if they can overlook the bias toward USB units that completely ignores price/value.
Besides, Picoscopes are cheap! The base version of the 4-channel unit he has is less than $3,300. :D
[/sarcasm]
Sample-rate is impressive though, at 5 GSa/s. But at that price, with no screen, no controls, etc. I would certainly hope so.
-
All in all it's a Picoscope advertorial. Nothing more.
Yep! More than evident.
If you want to play around yourself, I’ve got a Python script that applies analog filtering to a square wave and plots the results, available here.
https://github.com/colinoflynn/scope-bw-example (https://github.com/colinoflynn/scope-bw-example)
Yes, I played with this script, it looks interesting, but I can't set the input signal rise time.
-
The author also doesn't get that the 16 bit 'resolution' is coming from oversampling an 8 bit ADC. That is a bit optimistic to say the least. All in all it's a Picoscope advertorial. Nothing more.
Picoscopes has scopes with ADC's that has more than 8 bits (12 & 16 bit depending on model) and in their software it is also possible to select oversampling for up to 4 bits extra.
-
Now closely investigate the requirements for meaningful oversampling. My Tektronix oscilloscope also has oversampling to get to 11 bit but it is very easy to get false results. There is much more to oversampling than meets the eye which is why they sell ADCs with many different bit lenghts instead of one 10GHz single bit ADC. From my own experience with Picoscopes I know you can get funny results when oversampling is enabled.
-
Then goes and builds that knob box:
Oi, who are you callin' a knob box ? :P ;D