Hello, I have a new PCSGU250 with latest drivers and SW Rev. 1.12 downloadad from Vellemann homepage, operated on a WIN7 system.
In oszi mode, it only measures 1/10 of the signal voltage. E.g., if the input is a rectangle profile with +/- 5V, the oszi shows +/- 0.5V (probe setting 1x, at the probe and in the SW). Additionally, on the oszi the rectangle is not a rectangle: the leading edge is rounded, only the trailing edge is rectangular as expected.
The 1/10 effect appears as well with input from the internal generator, as with input from a 1.6 V battery. And it’s the same if I use the originally supplied probe (1x setting), or a probe from another oszi I own.
Do you have an idea what I did wrong?
I would like to upload an image but I didn’t find how to do.
Do you see similar symptoms as described in this thread: viewtopic.php?f=10&t=10108
Or - is the attenuation constant and exactly 1/10 on both channels and on all V/div ranges?
Maybe the probe with x1/x10 switch is defective.
Does the attenuation increase to 1/100 in position x10?
If not, the probe is defective (always attenuation 1/10).
I have tested the scope with the originally supplied x1/x10 probe, and with a definitely non-defective different probe (w/o x1/x10 switch, from another scope) using a 1.6 V battery as input. The attenuation 1/10 is the same with all probes.
Thus, the originally supplied x1/x10 probe should not be defective.
Additionally, I have attached the definitely non-defective different probe (w/o x1/x10 switch, from another scope) to the scope and directly connected the probe tips to the BNC output of the signal generator. The attenuation stayed at 1/10.
Thus, the function generator should be ok.
Shall I perform further tests, e.g. the test with a direct cable?
[quote]Shall I perform further tests, e.g. the test with a direct cable?[/quote]Yes, please.
Please check also the attenuation with the originally supplied x1/x10 probe when the switch is set to x10 position.
Is the signal amplitude on the screen 1/10 compared to the signal amplitude you get with x1 setting?
Do not change the software setting while doing this test.
*** the scope and the originally supplied x1/x10 probe are ok and are both working fine! ***
The reason of the 1/10 attenuation was the probe from my other scope. Yesterday I found that this is a x10 probe.
What I did from the beginning, was:
I switched on the new scope, connected the originally supplied x1/x10 probe to input #1 and the x10 probe from my other scope to the generator output. Then I connected both probes to measure the generator output, and started the oszi. Because the probe from my other scope is a x10 probe, I saw only 1/10 of the generator output on the oszi. Since I erroneously supposed the x10 probe from my other scope to be a x1 probe, I wrongly blamed the originally supplied x1/x10 probe (or the oszi) for the 1/10 attenuation.
the test with the 1.6 V battery was exclusively performed with the x10 probe from the other scope, confirming my erroneous belief that the scope might be defective.
So - sorry for my mistake, and thank you for the excellent support in this forum.
