Phase noise is an issue, however, adjacent signals in the filter passband seem to have more of an impact on the ability to decode weak signals than the phase noise associated with narrower filters. I have been able to decode weak DX stations with 400Hz and even 250Hz filters that I could not decode at all with wider filters.
73, Bob - N7RJN On 4/21/14, 10:26, "Jim Brown" <j...@audiosystemsgroup.com> wrote: >On 4/21/2014 10:05 AM, Joe Subich, W4TV wrote: >> There are, of course, exceptions to that rule. When there is a >> very strong signal in the passband that is causing the receiver >> to reduce gain to the point that a weak signal is not copyable, >> a CW filter (400 Hz) centered on the weak signal can often make >> the difference between copy and no copy. > >Yes. But the important thing is that "less is more" -- that is, the >phase shift occurs in the skirts and in the passband near the skirts -- >so when reducing bandwidth, stay as wide as you can and still reduce the >strength of the QRM. > >73, Jim K9YC > > >______________________________________________________________ >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 n7...@nobis.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
