I don't have many light-dimmers in my house right now, but I'm doing some renovation, adding recessed lights in some areas that I have temporary open access to the floor joist areas and circuit runs, and I'm noticing some radio-unfriendly behavior in the first dimmer I've installed.
I've been looking on digikey for "power line filter modules" and yes they have hundreds of them. They are all, I believe, designed to be installed in appliances and devices of all sorts, inside their respective housing, enclosure or cabinet, and wired on the power-input side of the device. This is presumably to prevent wide-spectrum electrical noise from traveling back from the device to the branch circuit and hence causing the entire circuit to act as a broadcast antenna.
Most of these filters range from $15 to $30, come in a variety of inductance and current ratings, are all housed in a metal can with mounting tabs, have connection options such as spade tabs, screw terminals or posts, or wire leads.
So my first observation is that none of these is what I would consider to be mountable as infrastructure devices that you might locate in an inaccessible place, such as you would a junction box, even if the device is electrically "safe" from a durability / longevity point of view. So if I wanted to use one of these on the input side of a dimmer control for a dimmer controlling say 4 lights, and potentially also put one on the output side (?) I think I'd want to mount them inside a junction box, which is not difficult. Even if these devices have MTBF ratings in the hundreds of thousands of hours, I do wonder about the really long-term installation of these devices in areas that would be somewhat difficult to reach years from now (behind walls, under floors, etc).
So besides where on a circuit these filters should or could go to achieve maximal EMI/RFI filtering effect, I was wondering if anyone else has used these particular devices for this purpose.
Or am I overlooking purpose-built infrastructure-mountable or load-center panel-box mountable products that are easily obtainable, reasonably priced and equally effective?