[Elecraft] [Elecraft-K4] K4 CW and keying Rise Time

[Wayne Burdick]

We went to great lengths to create an ideal sigmoidal (raised cosine) rise/fall characteristic for our CW keying envelope. It is set at approximately 5 ms and will not be shortened for any reason. Elecraft rigs don't click.

We also ensure that ALC never interferes with the CW keying waveform. During rise and fall, ALC is open-loop, allowing the characteristic curve to be presented to the output stages.

The result of all this is the narrowest CW keying bandwidth possible consistent with crisp on-the-air sound.

73,
Wayne
N6KR



> On Nov 4, 2019, at 12:21 PM, Dan Atchison via Groups.Io <N3ND=aol.com at groups.io> wrote:
> 
> I am hoping that the K4, like its predecessor the K3(S), does NOT give a user the ability to change its CW rise times.  
> 
> I believe the K3 is designed for a 5ms rise.  Many, if not most, other manufacturers allow as little as 1ms resulting in CW signals that reach beyond 1kHz of bandwidth by creating horrible key-clicks.  Indeed, their "default" values can be too short.  To what end?  Unscrupulous users setting it so their clicks help keep their run frequency clear?  Terrible to think that but I have heard some station owners admitting same.
> 
> Last weekend's CWSS had many, many horrible key-click stations - some from notable contesters.  I realize that things other than a CW rise time can give cause to key-clicks (antenna connections, hot-switching, etc.), but newer radios shouldn't be the culprit - yet they can be because of manufacturer's oversight (or under-thought).  
> 
> I've never heard of a short CW rise time being an advantage other than to create havoc. There is a happy medium.
> 
> Dan - N3ND
> 
> 
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