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Re: Topband: "Thinking out loud"

To: k1fz@myfairpoint.net, Topband <topband@contesting.com>
Subject: Re: Topband: "Thinking out loud"
From: "Richard (Rick) Karlquist" <richard@karlquist.com>
Date: Thu, 22 Dec 2016 12:56:21 -0800
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Crystal filters are known to have a 3rd order intercept
point.  Depending on how many AM BCB stations impinge
on your filter, you could get intermods.  Switching
in an attenuator ahead of the filter should help,
if you can stand the increase in noise figure.

Rick N6RK

On 12/22/2016 12:41 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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