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

[Jim Brown]

On Tue,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.

Yes, but that's RX bandwidth, VERY different from occupied bandwidth. 
The issue is RX bandwidth is the TIME (phase) response -- every change 
in amplitude is accompanied by a change in the phase response, that that 
phase distortion (remember, phase is time) blurs the code elements 
together.

> So you need more bandwidth for super high-speed CW because you need to 
> shorten the rise and fall times. 

You need more RX bandwidth, for the reason described above.

> But the occupied bandwidth doesn't change as you vary the speed.

Right. Occupied bandwidth is your "footprint" on the band -- how much 
your signal is spread out.

73, Jim K9YC