GC_ET_AFX_CW_FiltAAN.html

2021-01-06   06:40:44

Morse-Man

 


*** Yet Another Analog CW Filter ***  AFX_AAN_Q34 ***  ( click image )

 

*** Twin Notch Filters around a CW Filter,  Max Notch "Q"=10+10=14 .
*** The  AFX-AAN  has broader Top Band and Steep Sides at v=7 .
***
*** The "AAN" Design utilizes Twin Notches for Narrow PassBand, rather than narrow filters.
*** This 11 stage design is better than the "7N" , but more complex than the standard AFX.

*** The main benefit is a good steep sideband curve down to -36 dB.
*** The main problem is that the pair of Q=10 filters must be extremely accurately aligned
*** (1) with each other ( exactly 650Hz or 750Hz )  else severe distortion of the notch will occur. 
*** (2) with the f(700) centerband freq ,  the  offset is  only  +/- 50 Hz .   
***      

AFX-AAN-Q235-2-S-b.png

 

 

 

Here, the Green trace is "W"ide and the Red trace is "N"arrow. 

AFX-AAN-Q235-2-B-a.jpeg  
AFX-AAN-Q235-2-B-b.jpeg

 

*** No Double-Notches here, but very steep side walls, to down to -36 dB.    

 

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