I believe that you'll find that is true of any filter. By cutting the tone frequency almost in half (800 to 440 Hz), you almost double the effective width of the passband. That leaves more room for the keying sidebands which means less "ringing" or stretching of the keying transitions.
(I like lower frequency tones too.) 73 Ron AC7AC -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Pierfrancesco Caci Sent: Sunday, May 12, 2013 1:25 AM To: [email protected] Subject: [Elecraft] [K3] APF and Pitch Someone mentioned that APF rings less when pitch tone is set to 440 Hz instead of 800 Hz. So, I'm trying and it indeed seems to ring less. Anyone else hearing this? Is this some DSP effect or a psychoacustic effect? Condition of test: 200Hz 5-pole filter DSP BW 50Hz RF gain backed so that signal is barely audible with no APF RX Audio EQ bands 4 and 5 set to 0, all rest down -6 Pf -- Pierfrancesco Caci, ik5pvx ______________________________________________________________ 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
