[ICOM] Fwd: Re: Hope to see a roofing filter for the IC-775DSP

[Cletus W Whitaker]

de WB2CPN    South Central Pennsylvania      2004.09.12

Adam,  Although I never heard it called a Roofing Filter,
but the AT&T people, (Bell Labs really), came up with the
idea, and patented it, for shifting a band of frequencies,
say 960 KHZ, up or down a moderate amount in their design
of their LMX-1, part of their L-3 Carrier system.  They did
it for exactally the reasons you indicate.  There's also
a considerable saving in filter hardware.  Bell terminology
was Master and Sub-Master.  That was a long time ago.

73  Clete