If your scope was calibrated 15 days ago by Q-Service, you
need to get it back to them.
I have a suspicion that what you are describing is a retrace
problem (Z-Axis), but, I am having some trouble following your
meaning.
Whatever the problem, it should have been discovered when the
calibration was done.
-Chuck Harris
Panos wrote:
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Hi Chuck,
Yes I have a problem about the trigger in the vertical amplitude in 200 mV and below, AC or DC input coupling at any horizontal timing setting. This will disappear only if I set Noise or HF Rejection coupling. On screen it look like a second sweep identical to the main sweep during the trigger in a signal. This happen at any of the two first input channels 1 or 2.
Initially I did not understand what exactly was the problem, because I was using the calibrator of oscilloscope with my x10 probe as a source.
So during the triggering I was seeing the upper and lower faces of the square wave sweep signal to roll like a straight line left or right on the screen.
I have checked the output of my calibrator on another (Protek) oscilloscope, and the trigger working perfect in all horizontal settings.
So I thought to feed the same amplitude signal 400mV p-p in my oscilloscope from my CFG253 external generator, using a sawtooth or sinewave signal at 1KHz.
¦³hen the second waveform was clearly visible.
This second waveform will be moved left or right on screen using the trigger level, but never disappear except if I using the Noise or HF Rejection coupling setting.
It looks like it can't work correctly the trigger level, or better off having a poor trigger.
Maybe i will be better to do a video about this as you will better understand what I mean.
As a memo must I inform you that in this oscilloscope all the PSU capacitors have been replaced with alternate Nichicon type, and also have been calibrated before 15 days from QService.
Panos
