Posted by
Bill Coleman-2 on
Nov 13, 2005; 3:05pm
URL: http://elecraft.85.s1.nabble.com/CW-Pitch-600-Hz-or-700-Hz-or-what-tp383635p383646.html
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:
[hidden email]
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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