Preselectors
 

Yes, Hans, that is what I would call it a notch filter. A notch filter
is tuned to one frequency. Using a relativly hi Q circuit can fix
certain kinds of problems right away. That is if it is coming in on
the antenna. Very easy to make with just a few parts.

Preselectors
 

Notch filters.That's like them thingys the DirecTV installers just
Loveeee to throw down in our driveways.
cuhulin