Topband: "Thinking out loud"

[Wes Stewart]

The SNR is set at the antenna. There is a persistent desire to move the 
selectivity closer to the antenna, however....

With modern "bullet-proof" front ends, filtering can be delayed and done at 
i-f.  In fact, with H-mode mixer front ends, the IMD in the following filter can 
be more of a limit on signal handling than the mixer.  See: 
http://martein.home.xs4all.nl/pa3ake/hmode/roofer_intro.html

Imagine trying to build a multiplicity of such filters to cover the 160-meter band.

Wes  N7WS


On 12/22/2016 2:44 PM, K1FZ-Bruce wrote:
> Thanks Mirko,
>
>
> Very Good information.   What is needed is to reduce noise lower than signals. 73
> Bruce-k1fz
>