http://www.elecraft.com/K3/Roofing_Filters.htm
On Mon, May 12, 2014 at 9:45 AM, Jack Brindle <[email protected]> wrote: > Jerry, > > Why do you say it has been corrupted? This is exactly the purpose for the > Roofing Filters in the K3. > > Jack B, W6FB > > > On May 12, 2014, at 9:33 AM, Jerome Sodus <[email protected]> wrote: > > > 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:[email protected]] On Behalf Of > Bill > > Turner > > Sent: Monday, May 12, 2014 1:07 AM > > To: [email protected] > > 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:[email protected] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to [email protected] > > > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:[email protected] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to [email protected] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
