[Elecraft] [K3] CW Speed & bandwidth (was Tokyo Hy-Power HL-1.2KFX amp interfacing (to ALC or not to ALC?))

[Vic Rosenthal 4X6GP/K2VCO]

The relationship of bandwidth and speed is that for given rise/fall 
times, increasing speed will reach a point when the code elements blur 
together.

So you need more bandwidth for super high-speed CW because you need to 
shorten the rise and fall times. But the occupied bandwidth doesn't 
change as you vary the speed.

The K3's keying waveshape and rise/fall times (the shape is important, 
not just the time) are good for far faster CW than I can send!

73,
Vic, 4X6GP/K2VCO
Rehovot, Israel
http://www.qsl.net/k2vco/

On 29 Mar 2016 22:36, Jim Brown wrote:
> On Tue,3/29/2016 11:28 AM, Lynn W. Taylor, WB6UUT wrote:
>> On 3/29/2016 10:38 AM, Jim Brown wrote:
>>> WRONG! CW speed has NOTHING to do with bandwidth, which is determined
>>> by RISE and FALL times of the keying waveform and distortion in the
>>> RF stages.
>> So, I can occupy zero bandwidth at 10,000 wpm CW and my occupied
>> bandwidth will be the same as 5 wpm as long as the keying waveform is
>> right?
>
> No, because even the best rise/fall waveform has SOME harmonic content,
> and CW speeds of 10,000 WPM have no practical meaning. But you CAN
> occupy extremely narrow (a few Hz) bandwidth with a steady carrier,
> because there's nothing to excite IMD. Bandwidth would be greater than
> that only to the extent that the carrier is modulated by power supply
> noise or phase noise. And, of course, any distortion in the RF chain
> will produce harmonics.
>
> 73, Jim K9YC
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