[Amps] Slow start-up of Amps on CW

[Jim Brown]

On 3/12/2024 2:40 PM, Robert W5AJ wrote:
> Best I can tell, FTdx10 CW with 6ms rise time is in par with K3 looking 
> at QST In Depth review

Fast rise time CAUSES clicks; beginning with the first K3, Elecraft uses 
a carefully shaped keying waveform that they call "sigmoidal," (which 
I've heard described as a raised cosine) to provide nice sharp keying 
without clicks. I've heard that after a bad ARRL review for for their 
6500 series rigs, they adopted that shaping or something like it.

But rise time is the wrong thing to measure -- a spectral plot showing 
sidebands with a string of dits shows where the bodies are buried.

Likewise, modulation with a sine wave, or even an IMD pair of sine 
waves, fails to expose splatter caused by processing like Yaesu is 
(was?) doing in those rigs.

Splatter running VHF/UHF rover is far less likely to cause QRM except 
during band openings on SSB.

FWIW -- I love my K4, but am still quite happy with my 2008-vintage K3 
with upgraded synth.

73, Jim K9YC
> 
> It is interesting to watch the CW signals now with the BandScope
> more so during CW contest!
> Still own the K3 but I'm not likely to sport (Buy) a K4
> The FTdx10 is ideal rig to carry on the 50Mhz rover trips, gets me band 
> scope & built in sound card
> 
> 73 Robert W5AJ