1) The USB cable had a loose connection. At first I thought it is up to the USB port on the device, but fortunately the plug of the supplied cable DSO side was of the minimal design is too small. The exchange for a different cable resolved the issue.
2.) One of the two supplied samples also had a loose connection. Again, I was afraid it's up to one of the MCX jacks of the unit. Luckily it was also "only" the plug of the sample. Prudent bending the outer elements of the plug with your fingernails brought better "bias" and also corrected this problem.
3.) The two analog channels CHA and CHB did not proceed at the zero point (CHB was easy and even CHA by almost 2V shifted upwards) so that the voltage display was incorrect. Calibration inside the firmware resolved this problem. The unit had this not be screwed. Calibration is not described in the supplied manual and is somewhat hakelig. Storing the calibration data will not forget! The calibration of the curve on the potentiometer inside the unit, I have not done in my unit because it looked decent.
4) The supplied instructions was in addition to the fact that it is only English and Chinese, also copied so bad / printed that one on the pictures (with Chinese characters in English text) a lot of things can not detect.
5.) The built-in signal generator is apart from the square wave signal an absolute disaster. Rising and falling edges are more like a staircase than a line. This is true for triangle, sawtooth and sine alike.
6.) measurements already towards the MHz range are so inaccurate and untrustworthy by the representation of the curve that you can not really take advantage of higher frequency ranges. Where exactly are the limits, of course you can find out with a comparison measurement using a laboratory instrument.
Before I could eliminate the above problems and the inadequacies accepted, I was inclined to return the device. Up to this point my vote would be at a star.
But if one accepts some limitations and inadequacies or "repaired", you get a nice toy for the occasional hobby use. That this pocket device can not keep up with a laboratory instrument was clear to me and I did not expect. Nevertheless, the device costs about 140 euros and is thus certainly not a cheap bargain.
For my reviews I asked myself the following questions:
- One can expect that the device is delivered with ordinary cables?
- One can expect that the device is delivered calibrated?
- One can expect that a manual is printed properly?
- One can expect that the device has an integrated (at least in the kHz range) ordinary signal generator?
- One can expect that your device (MHz range) measures properly at higher frequencies?
Up to the last question, I would answer all questions with "yes". Bottom line, you have to expect to have to put the device first in a reasonably functioning state.
The range of marks star is in my view at 1-4. You can justify anything but questionable. But since I can live up to now solve the most problems with the device, I still forgive rather flattering 4 Stars of technology enthusiasts. Whether the device will retain its star, will turn out in the context of future use. Above all, I am very excited about the durability of the connections (especially the MCX jacks).
In addition I can still supply later the following information. Yes, the device can be expanded with Apps. For this purpose, are 2 of the 4 memory areas available (range 1 and 2 are probably required by the stock firmware, which I initially do not want to replace it with another available). But these apps are not as numerous as it seemed at first. Moreover, there is in most apps, the problem that they have been programmed for the 2MB version of the device and file operations such. As saving of screen contents on the 8MB unit does not work without effort. Should anyone know a source that provides 8MB versions of the popular apps, I would be very grateful for an indication.
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NOTE: All statements made by me are exclusively linked to the experiences made by me and on my own personal opinion on this device. I do not intend to rob anyone his peace of mind or to offend the good people in our country.