@qu1ck:
When signal is out of range the values are displayed in red as indication that they are incorrect. I think numbers and traces should still be displayed even signal is out of range. They still give some information about a signal.
Something wrong below 0.5V in DC
Re: Something wrong below 0.5V in DC
@jye1 Thank you for your information.
Re: Something wrong below 0.5V in DC
@jye1
But it doesn't always turn red. If you follow Macross' second video closely at 0:48 the scope shows a flat trace near the middle of the screen and Vpp is 0.01v (within noise margin), which is very misleading.
https://www.youtube.com/watch?v=Q2SjAiwbBlE
That is the exact situation that I would like to see fixed. If the overlay numbers turned red that would be fine, I would know not to trust them. But currently the device gives no indication that it detects a signal and can't show it with current settings, It's exactly as if there was no signal.
But it doesn't always turn red. If you follow Macross' second video closely at 0:48 the scope shows a flat trace near the middle of the screen and Vpp is 0.01v (within noise margin), which is very misleading.
https://www.youtube.com/watch?v=Q2SjAiwbBlE
That is the exact situation that I would like to see fixed. If the overlay numbers turned red that would be fine, I would know not to trust them. But currently the device gives no indication that it detects a signal and can't show it with current settings, It's exactly as if there was no signal.
Re: Something wrong below 0.5V in DC
@qu1ck:
In that case the display means it detected a signal with frequency of 0Hz, i.e. DC signal. Maybe we should display 0Hz instead of a dash line for frequency. Same for PM and Duty cycle. Only keep Cycle displayed as dash line.
In that case the display means it detected a signal with frequency of 0Hz, i.e. DC signal. Maybe we should display 0Hz instead of a dash line for frequency. Same for PM and Duty cycle. Only keep Cycle displayed as dash line.
Re: Something wrong below 0.5V in DC
@jye1
But that is wrong, there obviously is a 1khz 0.1v signal with dc offset on the input. It shouldn't show 0 khz.
But that is wrong, there obviously is a 1khz 0.1v signal with dc offset on the input. It shouldn't show 0 khz.
Re: Something wrong below 0.5V in DC
The frequency counter works like this. The average of signal is first calculated. Then it counts the crossovers of the signal with the average in a given time interval to obtain frequency. To get rid of the interference of noises crossover is counted only if the level difference to the average is greater than a threshold. For the Shell this threshold is about 1/3 division above and below average. So the 0.1V signal in the said the situation won't be counted.
Re: Something wrong below 0.5V in DC
jye1
Ok, that explains why frequency is not counted but not why the trace is flat and Vpp and other measurements are showing wrong values.
EDIT:
Wait, no that doesn't explain the frequency counter either. How come on a lower sensitivity 0.1v is enough to pass the threshold and trigger the counter but on a higher sensitivity it's not?
Ok, that explains why frequency is not counted but not why the trace is flat and Vpp and other measurements are showing wrong values.
EDIT:
Wait, no that doesn't explain the frequency counter either. How come on a lower sensitivity 0.1v is enough to pass the threshold and trigger the counter but on a higher sensitivity it's not?