You are experiencing interference in your VHF receiver. You have determined that signals from two nearby transmitters are mixing in your receiver to cause the interference. What device can you install to reduce the interference?

When signals from two separate transmitters mix inside your receiver to create an unwanted signal, this is known as intermodulation. This happens when the receiver's front end is overloaded by strong out-of-band signals, forcing the components to operate non-linearly. To stop this mixing, you need to prevent the strong offending signals from reaching the sensitive RF circuitry. Installing a suitable filter (such as a band-pass or notch filter) at the receiver's antenna input will block the unwanted frequencies while allowing your desired VHF signals through.