Antenna Switch RFI Solutions
Coax antenna switches generally only switch the center conductor of the coax and all the coax braids remain connected in parallel summing the common mode noise off ALL coax lines onto the coax selected - this means you may be picking up common mode noise from coax lines that are not even connected to the coax antenna selected. The only practuical solution is to isolate the coax braids from each other BEFORE they connect to the antenna switch as shown in the picture for a simple 2 position antenna switch.

Palomar Engineers TUBE feed line chokes are designed to have 2-5 times more choking impedance over a broader frequency range than competitor units in similar packaging. Each choke has the choking impedance and effective frequency range on the product label so you can choose the product best suited for your application.