[Elecraft] Filters

[Don Wilhelm]

Clay,

We are not talking about shifting the pitch of the signal by 50 Hz, we 
are talking about enlarging or restricting the pitch at only the low 
frequency end or the high frequency end by 50 Hz.
The LowCut and HiCut controls are like the Bass and Treble controls on a 
car AM/FM radio.  Think what would happen if your radio's Bass control 
were reduced by 100 Hz instead of 50 Hz - the difference is insignificant.

Oh yes, the Bass and treble controls on that  AM/FM radio are not 
calibrated for precise frequencies like the K3 HiCut/LoCut controls are, 
so we "use our ears" to determine what is best.  We should do the same 
for the K3/K3S/KX3/KX2.

There is no communications effectiveness for frequencies below 300 or 
400 Hz (0.30 to 0.40) on the low cut side, and there is little voice 
recognition in that range.  The effective range for voice recognition 
begins at about 500 Hz, and extends to about 2600 Hz.  That is for 
recognizing the characteristics of a particular voice pattern we are 
familiar with.  For communications effectiveness, we can reduce the 
listening range to 500 Hz to 1700 Hz and still communicate with clarity.

73,
Don W3FPR

On 7/1/2018 10:20 AM, Clay Autery wrote:
> I don't have "perfect pitch", but do have extensive music experience if 
> that matters....
> 
> Single tone, single voice, or an orchestra....  50Hz off freq. is enough 
> to make me want to drill holes in my head.  I can easily distinguish 
> below 10 hz, and sometimes 5 Hz.... and my ears are damaged from years 
> of rotary-wing flight/maintenance, small (and larger) arms reports.
> 
> That said...when using Lo/High/Shift/Width, the 50Hz resolution is being 
> used in a "relief from distractor" mode, so it is less of an issue, but 
> there HAVE been times that I wished for a slightly finer resolution.