[Elecraft] K3s - 80W on 160 - Resolved

[Jim Brown]

On Thu,12/22/2016 3:59 AM, Bill W4ZV wrote:
> Another reason to run higher voltage is improved IMD performance on SSB
> transmit.  Lots of info available from previous threads.  I've been running
> 14.5 at the K3 terminals on multiple units for over 5 years with no
> problems.

Bill,

IMD also affects CW. What we call CW is not "continuous wave," it is a 
continuous wave that is 100% modulated by a rectangular wave. That 
rectangular wave is rich in harmonics, and excites IMD. We hear it as 
clicks. This can be clearly seen on slides 8-16 of 
http://k9yc.com/P3_Spectrum_Measurements.pdf Slides 8, 9,and11 show the 
spectrum of a real "continuous wave" -- that is, a steady, unkeyed 
carrier. Slides 14-16 show the spectrum of dits at about 30 wpm. The 
difference is the keying sidebands, and those humps down below -50 dBC 
are IMD.

73, Jim K9YC