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

[Fred Jensen]

Ummm ... not exactly true but not exactly not-true either.  Occupied BW 
is a function of bit-rate [well, technically, number of signal 
transitions in a unit time, but they're closely related].  Fairly basic 
physics ... or I guess that's information theory now.  The faster you 
send, the wider your signal will be, guaranteed, you can't escape it. 
Like trying to drive faster than light, discarding angular momentum, or 
resigning from Linked-In.

Waveshape also affects occupied bandwidth, although the amount it 
increases the BW carries no information ... except for the useless fact 
that the dude with huge key clicks is still up there 15 KHz.

At "normal" CW speeds, aka D4C, the BW increase due to speed is hardly 
noticeable. With poor wave shaping, it is VERY noticeable, and 
information-free.

73,

Fred K6DGW
Sparks NV
Washoe County DM09dn

On 3/29/2016 1:03 PM, Vic Rosenthal 4X6GP/K2VCO wrote:
> 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.