Phono cartridge noises

He

doesn’t

have

hum. He just said so.

Although it’s a good idea to worry about routers/modem/repeaters, why go there when we know he has a giant radio antenna 1000 yards from his room? In medicine there is a canard about hearing hoofbeats and worrying that you are about to be trampled by zebras.

Skyy, you last wrote, "As soon as I plug the cables to the table(s) the noise is immediate..." This makes me envision the cable from your tonearm into the phono stage. Is that correct? This means the RFI is getting in anywhere from the connector input to the phono stage to the cartridge itself. Have I got that right? And you say your phono cables are shielded. Correct? Just to prove the source, I wonder whether you could put together a cage made out of metal wire fencing or screen (smallest holes practical) and place it over your turntable, completely enclosing it. (Ideally, you'd want the cage to have a bottom as well, running underneath the TT.)  If that affects the problem positively, that would at least tell you what to target with some more practical shield. Faraday cages need to be grounded, too. You could ground that contraption to the wall socket ground.

He doesn’t have “hum”, in the sense of 60 or 120Hz noise. He needs shielding from that nearby radio antenna, and yes, the shield must be grounded to have an effect. We don’t know whether even his cables are shielded. Seems to me the only thing to be gained by selectively breaking existing ground connections is the possible introduction of hum, which is not a gain. 

Define “injected”.

Anyway, did Skyy tell us he can select the phono inputs on his linestage, and if the tonearm is disconnected from the phono stage inputs, there is no noise? If he explicitly said that, I missed it. I agree that would suggest RFI is getting in upstream from the phono stage. Sky, is this correct?

Noromance, Airborne RFI can enter via the cables or any piece of equipment, in this case the phono stage. Once it gets in, it can be propagated by cabling anywhere. so why is the observation that phono needs to be plugged in contrary to the airborne hypothesis? Or are you only wondering whether the Faraday cage would help? I assume cables are shielded, although maybe not adequately.

There is no reason to believe that an SS phono stage would be less sensitive to RFI. In fact, an SS stage is more likely to be MORE sensitive to RFI, because an SS stage will likely have a wider bandwidth, not that that extra bandwidth, for example above 100kHz, is necessarily vital for audio.  Also, in this case, the RFI is likely to be airborne from the nearby tower. Thus adding filters across AC and audio inputs is not likely to completely eliminate the problem, although there is no reason not to try it. In the worst case, you may have to consider placing your phono stage inside a Faraday cage type of shield.

An in-line filter might not help much because it sounds like the problem is radiating from that tower. Shielding is needed.

Do you live in a city or suburbs? House or apartment? Are your phono cables shielded? Is your audio system on the same circuit with any appliances? Does day vs night make any difference?