I just replaced my one year old INRAD roofing filter of 8 poles for 2.1 Khz bandwith for another from same company,same poles but for 1.8Khz,so now the 2.1 filter is available for sale,original cost is $129 at Elecraft,I will ship this one to anywhere CONUS for $70
AD4C
"For a refined ham it is compulsory to own a k3"