need help with siglent 1202X-E - Page 1
Forum section: electronics / testgear

author: Spartan_001
author_rank: Newbie
timestamp: June 06, 2018, 12:08:45 pm
content: Hello there,I bought a siglent 1202X-E.This is my first oscilloscope and i don't know if this is normal.I plug the scope on the BNC but it is generating triangle wavei plut this link with the imagehttps://imgur.com/a/E1smo9Rsome help ?

author: evgen.05
author_rank: Regular Contributor
timestamp: June 06, 2018, 12:12:22 pm
content: it's an induced noise. It's ok

author: Fungus
author_rank: Super Contributor
timestamp: June 06, 2018, 12:34:48 pm
content: Try touching the probe with your finger, you'll get much more than millivolts.

author: tkamiya
author_rank: Super Contributor
timestamp: June 06, 2018, 03:08:48 pm
content: That's just probe picking up A/C from nearly wires. It's fine. Try shorting out probe tip with ground. It should go away or most of it.

author: tautech
author_rank: Super Contributor
timestamp: June 07, 2018, 01:49:17 am
content: Quote from: Spartan_001 on June 06, 2018, 12:08:45 pmWelcome to the forum.Entirely normal.It's EMI noise from within the scope and most probably it's originating from the display.Connect the probe to a real circuit and you won't see it.Enjoy your first scope.

author: bugi
author_rank: Regular Contributor
timestamp: June 07, 2018, 06:25:00 am
content: Quote from: tautech on June 07, 2018, 01:49:17 amOr possibly from the power supply radiating EMI using the power cable as antenna.That was the culprit on my scope (2304X), EMI visible all the way to 10-20cm in _front_ of the scope, and quite stellar on the back side near the cable. A simple steel U-beam, an item that by chance was laying around at the time, on top of the cable was enough to stop that. I have been looking for braided/shielded device power cables since then, but haven't found any for sale. Even "reinforced" (or whatever the term would be in English, with unconnected braid for mechanical protection) would probably do the trick, but only found such as bare cable or long extension cords, not as the device power cable.It is not a showstopper, though, as long as I remember to move the scope a bit away.

author: Fungus
author_rank: Super Contributor
timestamp: June 07, 2018, 08:56:32 am
content: Quote from: bugi on June 07, 2018, 06:25:00 amComes in handy for detecting ghosts.

author: radiolistener
author_rank: Super Contributor
timestamp: June 07, 2018, 09:09:28 am
content: Quote from: Spartan_001 on June 06, 2018, 12:08:45 pmNormally oscilloscope should display 50/60 Hz sine wave in such condition.This is electromagnetic radiation from AC power supply network in your home.But the sine wave on your screen is distorted with a lot of impulse noise.The reason for that are digital circuits and switching power supply modules near to your oscilloscope.Primarily it's oscilloscope switching power supply and display.The display is emitting electromagnetic radiation at high frequency (about 62.5 MHz for Siglent model).The switching power supply is emitting electromagnetic radiation at low frequency range (1 kHz - 1 MHz), but it has a square waveform and it means that it has a lot of harmonics.