Tube PHONO preamp interference - RFI, EMI, bad grounding?

@filipm it’s unclear to me what you tried with wifi? Did you physically unplug from the wall all your routers, access points, extenders, devices that receive and or broadcast wifi and Bluetooth? Turned off all mobile devices (including phones, smart watches, tablets, computers)? This will help identify the source inside your apartment. You said if you lift the unit up the noise reduces? This can mean your downstairs neighbors have some sort of a device that can produce this interference. There’s just too many things…smart switches, smart devices, wifi access points, etc

Also, how old are the tubes in the unit? It would be interesting to change the tubes to something like latest production JJs or Gold Lions. Since you didn’t experience this with your solid state phono stage, if you don’t find and can’t eliminate the culprit, one of the simple options will be to go back to a solid state phono stage.

@esarhaddon , that is not HAM or CB. You can tell it is packetized data and/or for packetized processing. The keeps are the demodulation of the envelope. I will see if I can extract the frequencies of the "beeps" as that may provide a better clue of the source. Some items have well defined packet frequencies.

@audphile1 , the change that is described by the op, appears to be a rapid change increase raising above the floor, then the change stops happening about 5 feet up. The floor is likely acting like a shield, but it could also be ground plane effects, or an inductive current loop.

@filipm Amazon has clamp on ferrite bead kits.
https://www.amazon.com/Tamicy-Pieces-Ferrite-Suppressor-Diameter/dp/B08BPHCXR3

Unfortunately it can be tough to get proper specifications of anything on Amazon. Different clamps work at different frequencies. Digikey will cost you more, but you know what you are getting. For $20 though, start with Amazon. Based on your comments about the output cables, put clamps on all wires input, output, and AC. Due to stray capacitance, every wire can act as an antenna.

@filipm , are you in a high-rise apartment building?  The reason I ask is they often host large cell tower arrays on the roof as well as antennas for other radio types.

I meant if I lift the device, the signal gets stronger. If I put it on the floor, it gets weaker. Just like a radio with an antenna.

Yes, I have just tried it again - turned of the only wifi router I have, along with a cellphone. It’s very simple over here, I don’t have any tv, more computers etc.

The device works well anywhere else I have tried it so far, that’s why I’m not suspecting the tubes. But I’ll try that. I just didn’t want to buy three more 12AX7 tubes before I try all the other options.

The building has 5 floors, I’m on 4th. The ceilings are 10 feet and the walls fairly thick. It’s in a city center.

I have just moved the stage to the other side of the livingroom, it’s about the same.

The best results are when I leave it on the floor - unplugged. As soon as I plug in any source - a TT, powered DAC without a source or just the RCA cables, it gets stronger.

- I’ll try a different turntable, the ferrite rings and then the tubes.

Going back to ss doesn’t sound very appealing :)

// oh, and the model is 834p deluxe without the volume knob. 1996

I wouldn’t waste money on new tubes. However if the 834 does not already have tube shields I would look into purchasing some aftermarket cylindrical shields designed to block EMI and RFI. Place one over each tube. Well designed ones also improve cooling and dampen microphonics .

It may NOT be HAM radio but HAMs have been using PACKET radio for many years. It was just one more place to look for a source of trouble.
Packet Radio : Software for packet radio use - The DXZone.com