[Elecraft] CW-Pitch 600 Hz or 700 Hz or what?

[Bill Coleman]

On Nov 12, 2005, at 10:50 AM, Karsten Eppert(DK4AS) wrote:

> I am in doubt about the optimum CW-pitch. I think I remember from  
> the old days, that the human ear has the best "built in" filter  
> around 1000 Hz, so I thought, CW-crystal filters should have a  
> pitch around 1000 Hz. Many commercial units seem to have 800 Hz,  
> the standard K2 has a suggested pitch of 600 Hz.

While a lot of older rigs had an offset for 1000 Hz, most newer rigs  
are 700-800 Hz. But long-time CW ops typically go for even lower  
signals, sometimes in the range of 400 Hz.
> 1. why is that so?

600 Hz is a good compromise between a lower frequency and single- 
signal reception. Much lower, and you're going to hear signals on the  
opposite side of the zero-beat.

> 2. I have set my K2 to 700 Hz but live with the very personal (not  
> supported by spectrogram) impression that the overall selectivity- 
> response is broader than it could be.

The adjustable filter has a narrow response, but it's skirts aren't  
that steep.

> Is it possible, that the NF-path is optimised for a 600 Hz- 
> response? If so, I would go through the entire re-alignement  
> procedure and reset everything to 600 Hz. Or is it all stupid  
> personal impression?

The response would be equally as broad at 600 Hz as at 700 Hz. I'd  
leave it.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901