Hi everyone!
... I wrote before that the scope makes up its own signal when the input frequency is above some value. Did calculations on it, and determined it is more then 43.3MHz This can be seen in the video near the end. I start at 80MHz, which it does measure, so hats of for that, but the amplitude is faked. My version next to it shows a much smaller signal. There only the up sampling is done.
When I lower the frequency the signal on both gets bigger and I have to lower the sensitivity. After that I start fiddling around the 43MHz. When I switch to 44MHz you can see the signal strength increase (Near 0:49 into the video) This is not the case on my version. ...
This "trick" has also been noticed in one of previous reviews:
https://www.ixbt.com/live/instruments/obzor-dvuhkanalnogo-oscillografa-fnirsi-1013d-s-7-dyuymovym-sensornym-ekranom-igrushka-kotoraya-sovsem-ne-igrushka.htmlA detailed study of the origin of such a suspicious smoothness of the oscillogram showed that at sweeps of 10 ns / div. and 25 ns / div. when the frequency of the input signal goes from 43.3 MHz to 43.4 MHz, the oscilloscope begins to turn any signal into the purest sine!
But in my case neither this or other accuracy/bandwidth/sample-rate related issues seem to be the most disturbing.
Not sure if this may be dependent on my particular device which may of course have some kind of "personal" manufacturing faults, but anyway -
periodically the scope just freezes at random intervals and stops reacting to actual input signals,
usually this happens with simultaneous turning to orange background color of one of menu buttons CTRL/V+/V- (the latter two cases usually then lead to respective change of V/div setting by the scope itself even without me doing anything at that time), also I've noticed that attempt to modify "T" settings menu leads after some random pause to "T" button background turning violet while background area to the right of it (where actual triggering settings are displayed) turns white at the same time and signal display also freezes, then after some ~10 seconds "T" menu opens again by itself (!) and sometimes disappears after a while but sometimes not and still needs tapping on "T" to close it, frequently just to repeat the same strange cycle again.
Tapping some button to "wake up" the scope seems to always work (i.e. the scope stops reacting to input signals and freezes the last view but still reacts to control actions) but it's really difficult to use the device when "activating" it every few seconds sometimes becomes necessary, the more that I still haven't noticed any "rules" for such behavior which retains the same random manner even regardless of whether any signals (which could provoke some response of device) are applied to scope inputs or not.
So my questions regarding this are the following:
- has anyone experienced similar behavior of this scope?
- any idea what could cause it (apart of specific hardware fault in my particular device)?
-
what orange background color of CTRL/V+/V- buttons and violet/white background colors of "T" menu area could mean?(seems like the latter color change should rather be implemented by device design than be a result of some accidental fault - regrettably, I couldn't find anything mentioned about this in manual)
Also by the way, for
pcprogrammer and all others who could be working on device improvement - maybe it is possible to implement some "error messaging" service into control system of this scope as by default there seem to be too much cases when seemingly unclear and unpredictable behavior is caused by device not reporting anything about its internal actual state and actions - which so remain unknown to a user.
The device I'm using is a never model which was ordered about a month ago from Aliexpress warehouse in Europe and is one of the last units from previous party i.e. before recent price increase.
And, in all aforementioned cases of input signal freezing the scope still keeps displaying "run" as an actual state, while trigger setting still remains in "auto" mode (in which sudden display freezing is best noticeable and most inadequate).
Thank you.