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Equipment / Re: Notch Filter for the 9330 kHz WBCQ SuperStation
« on: July 01, 2019, 1836 UTC »
You could always build a DIY Notch Filter. http://www.wa4dsy.net/cgi-bin/lc_filter4?FilterResponse=Bandstop&poles=6&CF=9.330&cfunits=MHZ&cutoff=.020&funits=MHZ&Z=50 I've used a site like this to calculate a 7 Element Chebychev filter when I've built the 13.560MHz mW TX. One trick to really bring this filter dead-nuts perfect? Use all variable CAP's. The inductors you can wind yourselves. http://www.wa4dsy.net/filter/filterdesign.html There are other filter design sites out there, but this one works pretty well.