Here's what I'm up to... Take a look  here:

http://www.wa4dsy.net/filter/filterdesign.html

Scroll down to the band reject filter

Input the following data:
Type
Poles -10
Center Frequency   1620
3 db bandwidth  1650
50 I/O Impedance in ohms

and look at the graph. I have interference from an 1620 AM 10KW broadcast station, only 1KW at night though...

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