Does anyone know of a good high quality bandpass filter that will allow the 763 to 775 MHz public safety frequencies through but block everything else? I mainly want to filter out cellular 4G LTE data in the 700 MHz band so I can install a good high gain antenna in the center of my car's roof and not get cellular overload. I found filters that do the opposite - they let in LTE but filter public safety but I have not found any that filter LTE and let in public safety. Is there one out there? Price is no object.