UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Origin of terms "Roofing filter" and "Reciprocal mixing"

Andrew2 · 19th Mar 2017, 10:17 am

Interesting that in that description, the 'roofing filter' comes at the 2nd IF. I've always regarded the first IF the place to put the roofing filter, so as to give max protection to all successive stages.
I wonder what the filtering arrangement after the first mixer was, and why wasn't that filter called the roofing filter?
Or maybe I'm reading it wrong.

19th Mar 2017, 10:17 am	#2
Andrew2 Nonode Join Date: Mar 2010 Location: Dukinfield, Cheshire, UK. Posts: 2,038	Re: Origin of terms "Roofing filter" and "Reciprocal mixing" Interesting that in that description, the 'roofing filter' comes at the 2nd IF. I've always regarded the first IF the place to put the roofing filter, so as to give max protection to all successive stages. I wonder what the filtering arrangement after the first mixer was, and why wasn't that filter called the roofing filter? Or maybe I'm reading it wrong. __________________ Andy G1HBE.