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

G8BBZ · 22nd Mar 2017, 2:52 pm

Hi All,
Radio Wrangler's mention of the Marconi White Noise test sets brought memories flooding back of many long hours as a junior engineer spent at (often remote) baseband sites on 1200 channel N+1 FDM/FM microwave systems sending noise down the line so that the more senior guys could find the source of some noise component that was putting the system out of spec. I carried a copy of "The White Noise Book" with me for a long time and still have it in my bookcase. Eventually I graduated to being the one trying to track down the source of the noise - but then the world went digital.
Happy days
cheers
Peter G8BBZ

22nd Mar 2017, 2:52 pm	#12
G8BBZ Pentode Join Date: Oct 2005 Location: Hebden Bridge, West Yorkshire, UK. Posts: 200	Re: Origin of terms "Roofing filter" and "Reciprocal mixing" Hi All, Radio Wrangler's mention of the Marconi White Noise test sets brought memories flooding back of many long hours as a junior engineer spent at (often remote) baseband sites on 1200 channel N+1 FDM/FM microwave systems sending noise down the line so that the more senior guys could find the source of some noise component that was putting the system out of spec. I carried a copy of "The White Noise Book" with me for a long time and still have it in my bookcase. Eventually I graduated to being the one trying to track down the source of the noise - but then the world went digital. Happy days cheers Peter G8BBZ __________________ Peter G8BBZ