Hello Bill, The term "roofing-filter" made sense back in the 1980's when I designed roofing-filters at 70 MHz. Bandwidths would be in tens of KHz. The purpose then was to protect downstream circuitry by rejecting very strong out-of-band signals that could cause overload; selectivity was not the purpose. Selectivity was done further downstream. So the term has become corrupted over the years. 73 Jerry KM3K
-----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill Turner Sent: Monday, May 12, 2014 1:07 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Roofing filters are misunderstood ORIGINAL MESSAGE: (may be snipped) On 5/11/2014 7:25 PM, Fred Jensen wrote: > I too think roofing filters are really not well understood. REPLY: A large part of the misunderstanding is due to the name. Whoever chose the name "roofing" did a great disservice. A better name would simply be it's function: 1st I.F. filter. That's what it is and that's what it does. I have always thought that "roofing" was a marketing ploy to imbue it with some kind of magical powers. 73, Bill W6WRT ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jso...@comcast.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
