Topband: "Thinking out loud"

[K1FZ-Bruce]

Tim,
 
My single crystal was in the 1950's. 
 
A crystal lattice could take in much of the 160 meter band and be pratical. 
 
Thanks for your input. 
 
73
Bruce

On Thu, 22 Dec 2016 15:49:12 -0500, Tim Shoppa  wrote:

       Bruce -  It has long been rumored that the big EU multi-multis 
have a crystal filter at their run frequency receivers. e.g. if they 
are running on 7003.4, they have a crystal filter in front of their 
receiver for 7003.4.  have never observed that in my visits but maybe 
in decades past, when receivers had less damage range, it would've made 
sense.  Also a good reason to put up a fight for ownership of YOUR run 
frequency  HI HI
 
  I believe EMRFD has a schematic for a single-frequency receiver, 
maybe not exactly like you described but similar in principle. Let me 
see if I can dig it up. 
 
Tim N3QE

On Thu, Dec 22, 2016 at 3:41 PM, K1FZ-Bruce  wrote:

 
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
 
 
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