possibly - but here a SW or MW AM radio not tuned to a station is a good indication - and that is cheap enough.
If it is true high frequency common noise (what you refer as RF) then the effects are more complicated as they appear and disappear over a length of cable for a given frequency - this is perhaps of more relevance if trying to ground them. However if there is RF noise there is typically many contributing frequencies so detection with a radio can still be effective.
BTW common mode detection can work by using your body as a grounding ‘ballast’
to some extent - you will need to couple your conductors with the common mode currents to a probe - and have the other probe grounded.
Common mode noise can also be caused by the back ground electromagnetic fields in a typical domestic environment can be easily seen. If you switch the input impedance up high and turn up the sensitivity - and touch the signal probe - you will see an induced voltage on the display. This is representing to the hum you some times hear when you touch a signal live input when it is not grounded. Typically this will be noticeable on phono and microphone inputs. If your oscilloscope shows a a degree of high frequency fuzz here as well - then that represents there are RF field strengths present too.
However consumer products are designed to work in these domestic environmets - so unless you have a very high level of background electro magnetic fields (unlikely for a home) then this sort of thing is going to be pretty much inconsequential.
If you are genuinely interested and looking at EMFs from devices and cables - get a little EMF meter probe - these are design to pick up/couple to EM fields and measure them … these have come down in price hugely - and can be quite an eye opener. You might not look at your iPad, Laptop or mobile the same way afterwards
Or get within a meter of a microwave oven when operating. Yikes.
I use an EMF meter regularly and what shocked me most was the things it flagged as being actually dangerous. The keyboard on a Yamaha electric piano… 600vm!
Most things are very benign and read close to zero for both E and M fields more than about a cm away. So anything problematic really stands out. The microwave, the piano, LED lights; they were the really “oh gosh” items.
Yes some Microwave ovens if not sealed properly or old will radiate… you might also notice this with reduced wifi performance for devices near the oven!!
Our QB2 in the kitchen nearly always cuts out when the microwave (about 2 metres away) is turned on. It’s on WiFi and will run for a couple of minutes until the buffer run out before stopping.
My Ethernet is not in anyway connected to my HiFi, I suffered from some low noise interference, maybe nearby cables? or maybe my 5G router? my Wi-Fi? Switched mode power supplies? I purchased a DC blocker/filter which has removed the interference, it has also changed the soundstage, more open, but a little flatter, difficult to describe.
I have a Roon server (home built), with connected NAS drives, and working with Roon/Qobuz, a musical combination! My Roon server feeds DSD256 to my DAC via USB, there is no noticeable noise now coming from my network. Indeed I might well try EoP again, that was reliable but noisy.
I am not the expert here, but i suspect it could be many things: ground loops, or common mode noise by SMTPs, LED lights or the power supply of your Roon Server. 5G itself would probably not cause a low frequency hum. May be try something like the Russ Andrews RF Router MKII. It reduced hum at my phono stage, albeit having a very subtle effect.
Yes, it’s on my to do list. It seems to be quite slow to heat things up even on max power - hopefully not because it’s leaking microwaves and cooking my brain!
No it’s not common knowledge because it is not correct. Both 2.4 GHz and 5GHz bands are susceptible to interference. They are called and allocated as ISM radio bands by the ITU (Part of the UN) , which means they can be used for industrial, scientific and manufacturing purposes without the need of a radio transmitting licence by the equipment owner. As such many devices share these bands other than just WiFi transmitters, which is why effort goes in wifi protocols to work well with otherwise interfering users.
The benefit of the 5GHz wifi band is there is greater bandwidth available which in turn means more users can share the band within a given area.
Sorry, I missed out a word. 2.4ghz is MORE susceptible to interference than 5ghz. A quick Google search would indicate it’s a widely held view for a variety of reasons.
I really think these days there is not much in it… much of that commentary you see on consumer/social web sites via Google etc of 5GHz wifi band being less used was prior to the mass adoption of wifi5 and was part of the ‘promotion’ narrative for the adoption of wifi5 (which of course could only use the 5GHz band). Later standards are back to using both bands again…
If I look at my own WLC I can see as much interference on 5GHz as 2.4 GHz. Professionally I see this as well across many thousands of APs in many environments which is why we have our APs re optimise which channels they are using regularly for both 2.4 and 5 GHz bands. However 5GHz is preferred because of the wider channel bandwidths and greater throughputs as well the greater number of channels compared to the 2.4 GHz wifi band with its limited number of channels.
But I agree on the 5GHz wifi band there are more options for mitigating interference than on the 2.4GHz band… however both bands are more or less equally susceptible to it.
I got the same brand today, by coincidence.
Of course i did some measurements right away.
In order to find out what common mode noise does to sound, i put the Nac 282 on phono stage (vertere phono 1 Mk2 L) and increased sound to half max so that hiss is well audible. Amp is Nap 250 DR.
Then i measured how much AC signal is on the Vertere DC input and its phono output.
![1000018963|375x500]The Vertere is fed by a Vertere challenger power supply fed by Audioquest Niagara 3000 with Audioquest Monsoon.
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Next i plugged in a power chord extender with usb charging ports to a socket next to the one that feeds my Audioquest 3000. The AC noise in both the Dc input and the phono output increased to over 100 V/m although nothing was plugged into the extender. But i could not hear a clear increase in the phono hum and hiss.
Next i plugged an the power chord of an LED light and switched it on.
The AC noise increased in both the DC input and the phono output to over 150 V/m. See images. Now i could hear a clear increase in hum and hiss.
My phono cable is a silver Kimber cable full with ferrit beads. The ferrit did not prevent the increased humm and hiss but may have reduced it.
So, i think in my system and the sound level i looked at, i can say that AC noise over around 120-150 V/m is audible if it impacts on a sensitive part of the system, such as the phono output.
I also compared the little AC detector to the EMF detector and it sounds alarm at around 100 V/m. So a pretty useful threshold i think.
