[Elecraft] K1 carrier rise/fall times unequal?

[Vic Rosenthal]

Don Wilhelm wrote:

> As far as bandwidth of the signal goes - the waveshape alone does not tell
> the whole story because the keying speed is also a primary factor - a 10 wpm
> CW signal is more narrow than a 30 wpm CW signal and so on.  

Actually, this is incorrect.  It is true that the faster you send, the 
harder the keying needs to be (otherwise the elements start to run into 
each other), so faster CW requires harder keying, which makes the signal 
wider.  But speeding up or slowing down does not change the actual 
bandwidth that the signal takes.  The bandwidth is dependent on the rise 
and fall times of the elements.

To the original poster:
Having said that, I suspect that it's a little more complicated.  You 
can have different shaped leading and trailing edges with the same 
overall rise/fall time, so just looking at a scope is not sufficient to 
determine whether your signal is clean.  I suggest using a second 
receiver with a sharp IF filter.  Adjust it so the signal from your K1 
is S9 and carefully tune across the signal.  If you hear clicks for more 
than about 500 Hz above or below the signal itself, then perhaps it is 
too wide.  Note that you cannot determine if a signal is too hard by 
listening ON the frequency of the signal, because the receiver's filter 
will soften what you hear.  What you are listening for is clicks on make 
and break when you do NOT hear the tone of the signal.

By the way, if you do have excessive clicks, you may be interfering with 
other band users even if you are well within the band, so if there's a 
problem you have to fix it!

73
Vic K2VCO