Best oscilloscope choice?

[watari]

BTW, the wave I expected from my Hartley circut is a sine like one, but the previous one (plugged) has a weird shape to me and i don't know if for you guys it will mean something.

Thanks!!

[TinselKoala]

I can't quite figure out what is going on there, but something sure doesn't seem right.

Can you show the screenshots that you get when you run the scope's "probe compensation adjustment" routine, done with and without the PC power supply plugged in? See the Manual, part 1.6, page 12.

http://www.electronicaestudio.com/docs/Hantek6022BE_Manual.pdf


You can also run the "function check", part 1.7, and the internal self calibration, 1.8, to make sure the scope itself is set up and working properly.

[watari]

Thanks for your advise TinselKoala.

I already did all of the things you say, but I've done them again just to double (or triple) check. I post the screen shots I took this last time.

Probe compensation: first one is plugged and the second one unplugged

[watari]

The fuctional check is ok. I've tried  plugged and unplugged PC and using both probes. All of them displayed the same results. According with its User's guide it has to show a wave of 2V peak to peak and a frecuecy of 1KHz aprox., and tha's what I get so everything is all right, then. Also I tried once more to calibrate being my PC unplagged.

After all of this, the same situation I explained previously remains.

Maybe the explanation does not go further than the fact that it is a cheap oscilloscope and it has its own limitations. What do you thing after all of this?

Thanks!!

[TinselKoala]

The calibration traces are showing that there isn't anything wrong with your scope, like a noisy AC power supply or something. I doubt if the "cheap oscilloscope limitations" have anything to do with this problem.

OK, let's figure this out.

In the post here
http://www.overunity.com/13842/best-oscilloscope-choice/msg381997/#msg381997
you are showing the traces at vastly different timebases, so I can't evaluate just what's happening.

But from your description it does sound like you are making a groundloop somehow.

Can you please post the schematic of your Hartley oscillator, including power supply, and show just where and how you are connecting the oscilloscope probes and ground references?