Topband: "Thinking out loud"

[K1FZ-Bruce]

We know that limiting the noise pick up from more directions of an antenna we can usually hear better. We also know  if we limit the noise from a receiver IF we can hear less noise, and better yet, if we
have a roofing filter earlier in the receiver we can eliminate even more noise  in relationship to the wanted  signals. 
 
What if we take it a step further, could we limit the band-with of the antenna signal with a crystal lattice for 160 meters before the receiver. 
Years ago I played  around with a single crystal at the input of an old tube type receiver. It was remarkable what I could hear on 40 meters, on what seemed to be one frequency. 
 
73
Bruce-k1fz
http://www.qsl.net/k1fz/beverage_antenna.html