IC cable to address RF coming from nearby FM station

@converge

Just out of curiosity, is it an AM or FM station you're having a problem with? Is this a stereo pair of balanced cables giving you RF in both channels (or just one cable)? Are you actually hearing the radio station through your speakers? Are the cables feeding power amps? Do the devices that are interconnected have XLR ins and outs that you're using, and you're not converting balanced cables to RCA ins and outs? I'm a Radio Broadcast Engineer, and have dealt with this type of problem for decades. Maybe I can help. 

Hello,

The RF signal is coming from an FM station, 97.5, that's about a mile from my house. The tonearm seems to be acting as an antenna. I can modulate the strength of the signal by grasping the tonearm cables at various locations along their length.These tonearm cables are integral with the tonearm and are terminated with XLR connectors. They feed directly into an outboard phono stage. All cables in my stereo system have hardwired XLR  connectors.

I'm hearing the RF thru both speakers.

At one point, I'd considered wrapping these tone arm cables with an adhesive-backed copper foil and then soldering a ground wire to the foil. But the foil would crumple as I tried to wrap each tonearm cable.

Thanks for your inquiry, Phil

I agree something is acting like an antenna. How long is the cable run from tonearm to phonostage and where is this unit located? Is it earth grounded to the buss bar in your service panel as the rest of your system should be?

Process of elimination: 1) have you tried a different phono stage 2) have you tried a different phono cartridge 3) have you tried a different set of phono cables; and if so, are the results the same? 

These tonearm cables are integral with the tonearm and are terminated with XLR connectors. They feed directly into an outboard phono stage.

...like within 3 feet of the turntable? The output of the phono stage is balanced XLR, and the 18' XLR cables feed a pre-amp input from the phono stage output? What phono stage are you using? 

@converge Hi there - Yes, I had a ugly situation from my neighbor who had a very illegal CB radio with a high power transmitter.  It was bleed into my stereo to the point I could hear the conversation.   Through process of elimination, I fixed it by using coax for my speaker cables.  I used two of them, grounded the shield to the chassis of the amplifier, which was Earthed, and using the center conductors of each to carry the signal to my speakers.  The speakers were Dahlquist DQ-10's and the center conductor the coax was 16g.  The shield was a heavy copper braid.  Unfortunately, I don't recall the brand name of the cable.  Over the years they disappeared somewhere in one of the moves.

What I suggest you do is put some ferrite cable clamps on the phono cables.  Since they are coax, they won't affect the audio signal but should squash the RF floating on the cables.  The word "some" here means three or four spaced evenly about the cable run.  Use a thicker wire on your chassis ground for the phono.  It won't reduce hum but it does make a lower impedance path to earth for RF.