[Elecraft] [K3] APF and Pitch

[Ron D'Eau Claire]

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: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Pierfrancesco Caci
Sent: Sunday, May 12, 2013 1:25 AM
To: elecraft at mailman.qth.net
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