CAP

you need a cheap chinese emi tester like wt3121, if your monitor shows higher than >0mV, it means there is something wrong with the grounding.

      Slender chinese emi tester like wt3121

      what freq range do we need exactly to measure, is EMF meter is enough?

      1. For example, PC monitor's fields, and what happends if I turn-on XMP profile in DDR4 (2133mhz, 3200mhz) - what freqs do I need to catch
      2. Mobile phone, laptop, chargers - what freqs

          simplex

          It is necessary to distinguish between the interference (emi field) caused by AC and the frequencies that are in the emi field. External emi can be measured with a device such as wt3121 (as shown in the photos at the beginning of this thread).

          frequencies can be measured with an oscilloscope.

          What's the problem?

          Even when your monitor will not emit any field (0mV), (at least that wt3121 sees), bad frequencies will still be emitted from your pc, monitor, walls of your house.

          The AC emit itself will always be present, that's physics. Only harmonics within this field have an effect.

          I don't know what frequencies exactly are projected when increasing the voltage of system components (cpu/ram/gpu)

            Slender
            Hope you understand that the "chinese emi tester" you're using is a glorified AM radios (at best) which isn't calibrated for measuring the necessary range you're trying to target, spouting random values.
            Take a look at this review for more information
            You're supposed to use a proper spectrum analyzer from reputable brands such as LeCroy, Keysight, Rohde & Schwarz, Tektronix for this type of troubleshooting, especially when approaching the 2.4–5GHz range.

                5 days later

                qb74

                yes i understand that. And yet it showed a problem. In my case the interference was breaking through to the pc from the metal table. And this is despite the fact that my pc was grounded. I still got 25-35 mV from the monitor screen and the pc. It was very interesting to discover this: I touched the pc case with my hand and the table leg with my foot and saw how the values ​​dropped to 0.

                  simplex
                  his build:
                  7600x
                  32 gb gskill cl28
                  klevv cras c930 m.2 1tb
                  gigabyte 4060 ti 8gb eagle
                  asus PRIME B650M-A AX II
                  antec c5 case white
                  cx750m 2024

                  All components are new, retail os system.

                      Slender All components are new, retail os system.

                      Interesting

                      New build dont have issues for 100 prc?

                          Slender

                          I got a wt3121 and my monitor is 0 mV. Near the laptop it is in red but low amount. I noticed that some walls of the room and especially the ceiling can go up to 300mV

                              simplex

                              sorry i dont know about eye pain for him but he had problems with graphics, input lag, image jitter, blurry, desync.

                              Perhaps it helped that he reduced the system consumption by half, compared to the 14700k and 3080 he had before, with the same PSU wattage (750w).

                                CAP

                                if your monitor has no emit, it means that it is grounded. Without connecting the laptop power, does it emit? Laptop shows some values when monitor (hdmi, monitor power) / laptop power disconnected?

                                • CAP replied to this.

                                    CAP I do not have an explanation, but I share a similar story. All the screens that started bothering me were used at home, specifically in one area where my desk is. At work I had far fewer issues, but when I took screens from work to try at home, then they started bothering me in both places. I do suspect some kind of electrical, grounding, or emission problem in that area at my home that made me sensitive to those screens.

                                      Slender

                                      I have done some more tester readings and now the screens shows some mV, depending on where I am located in the room but in the place where I work the monitor shows low activity, like <10 mV. If I move the computer table and I sit on the sofa the tester goes to >100 on the scren.

                                      When I connect the monitor to the table PC, on the same table, the monitor show >40

                                      The laptop show as well some some value both mV and uT.

                                        dev