[Elecraft] CW Transmit Filter Bandwidth

[Don Wilhelm]

Byron,

You are assuming that the CW signal shape is controlled by the TX filter.
It is not - that is done in the DSP and produces a clean single 
frequency signal that is quite good at TX phase noise and keying artifacts.
As long as that signal fits within the bandpass of the filter all will 
be well.  In other words, a 1kHz filter would not produce an improvement.

It might with some other rigs, but not with the K3/K3S because the 
filter is not the limiting factor - the DSP shaping and the low TX phase 
noise of the K3/K3S are the determining factors.

73,
Don W3FPR

On 8/21/2018 4:42 PM, Byron Peebles wrote:
> Don:
>
> I do understand it works, since every unit is shipped that way.
>
> My question is more in the vein of wouldn't using a 1kHz or less 
> filter be safer/cleaner/logical for CW?
>
> Obviously, not as a factory default, since only one filter is sure to 
> be there, but on a per-user basis.
>
> I thought years ago (before I had Elecraft) I read that a narrower TX 
> signal made for a stronger signal within that narrower bandwidth.
>