GC_ET_AFX_CW_FiltAAN.html
2021-01-06 06:40:44
*** 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 .
***
Here, the Green trace is "W"ide and the Red trace is "N"arrow.
*** No Double-Notches here, but very steep side walls, to down to -36 dB.
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