Shielding for FM tuner?

Hi Broubin,

Yes, a sheet of copper will act as a shield, so will aluminum or even mild steel, but not stainless steel. It will have to be grounded in order to drain any rfi/emi though. Before trying that, be sure that your tuner's power cord and antenna lead are nowhere near the cd player's power cord. I had the same problem with a cdp a couple of years ago and simply repositioning the coaxial cable solved the problem.

Both your CDP (actually the DAC part, not the transport part) and your computer are putting out RFI (radio frequency interference) from their power cords, which act like transmitting antennas (even though the power cord may have a ferrite collar at the component end.)

To prevent this, you need to replace the regular 3 conductor power cords with ones that have a foil shield (and preferably, a braided shield as well.) The shield(s) must be "floated" from the component end. That means the shield(s) are connected (together with the green ground wire) to the ground pin of the AC plug end only, and not to the ground pin at the component end.

The good news -- that oughta do it. The bad news -- shielded cords with floating shields are hard to find at retail stores.

Unfortunately, you can't just run out and buy one at Best Buy or CompUSA because of what it costs big manufacturers to get a UL listing on such items. However, they're easy enough to make yourself by cutting off the IEC end of a commercial shielded cord and then re-terminating it with a new IEC connector but without the shield connected to it.

If you're not so inclined, many of the specialty manufacturers of audio power cords make them with floating shields in a variety of price ranges, and most of them are represented here on Agon.

ferrite core clamp on filters on the AC cords outght to do the trick: Audioquest makes 2 models, I'd guess the larger ones would work better for this situation.