rigol 1052e came problems started

[crmaris]

Today I was testing my new rigol. The problem is that even with the PSU with no load it shows 100-120mV AC noise (it picks up noise probably by the PSU that gives power to my loader). However when I close the PSU of my loader there is again noise (40mV P-P).

In the mean time the stingray works flawlessly and does not pick up any noise.

I must miss something in the settings. Can anyone that has a rigol tell me his settings (especially Digital Filter's parameters).

Thanks!!

ps. I flashed my rigol to 100 MHz (and I have the new HW batch) but this is not the problem since I used again the same firmware that my oscilloscope had and I also tested the rigol with the stingray as a signal generator and the signals were fine.

[Makalu]

It's AC powered right? not USB powered like the Stingray?

[crmaris]

Yes AC. But when I use the stingray as a signal generator the signal on the rigol is fine.

[Oklahoma Wolf]

Can you limit bandwidth to 20MHz? If so, try that. ATX spec is 20MHz.

The Tektronix always picks up extra noise if I turn off the bandwidth limiting and let it run at 100MHz.

[crmaris]

Yeap. I already tried this but the situation is about the same (a little improvement)

[Oklahoma Wolf]

The Rigol must be picking up noise from elsewhere in the house if nothing in the testbed is doing it. We once had a TV set that introduced noise like that despite the fact it was one floor up and across the house. Until it was gone I couldn't load test with it turned on at the same time.

[Makalu]

yeah it's probably picking up some AC common mode interference somehow somewhere...I guess try different circuits but should share the same ground as the PSU under test. Can try floating the scope (put it on a two prong outlet with no ground)...it's hazardous but sometimes has to be done.

[crmaris]

thanks very much guys for your answers! I will try to find a solution and if not then I have to stick with the stingray (which is fine for PSU testing). The only thing that lets me down is that I spent 350 euros for the Rigol :(

Bellow is a screenshot of what I take when I plug the Rigol to my load tester (with the test PSU in standby and the PSU of the load tester on).

[crmaris]

finally the problem with the high ripple shown in the Rigol is the PSU that gives juice to my load tester. The thing that I cannot understand is why the Stingray does not pick any noise while the Rigol does. Ok the difference in bandwidth (between them) is huge but 120mV compared to 2-3mV of the stingray is also a huge difference. I tried different AC sockets to power the Rigol and the results remain the same, unfortunately.

[Oklahoma Wolf]

Forgot to mention I actually had a similar problem with the PSU that powers all the fans in the lab. Was using an Andyson MT9 for a while but it had to be swapped out after it started causing problems on the Stingray. Now I use an Antec CP-1000 in there. Scope readings were nice and clean again once it went into action.

Hooray for Delta :)

[crmaris]

I use an SFX Silverstone 450 because it is very small but if I want to use the Rigol it seems that I must swap it with a Seasonic (I have a X-560 sitting in my lab). I will use the Stingray for the moment.