[Elecraft] K3 Harmonic Distortion

[Brendan Minish]

On Tue, 2008-09-02 at 12:28 -0400, Jack Smith wrote:

> 
> However, setting the LIN OUT at 2 results in quite a bit better odd 
> order harmonic suppression, on the order of nearly 70 dB. 

This might be due to simply running out of usable bits to represent
accurately the harmonics at the low end of the K3 internal D to A side
of things. 

> By the time 
> LIN OUT is set to 5, however, the odd order suppression is reduced to a 
> bit more than 60 dB. At LIN OUT = 10, it's 45 dB or so where it stays at 
> all values of LIN OUT tested between 10 and 100.

The issue I have with this is that even with a quiet 24Bit semi Pro card
but the time you go to Lin = 2 you are some 40dB down on Full scale
input on the sound card assuming Consumer line level 

Leaving aside all other noise sources  this only leaves you with 40 to
50dB or so usable dynamic range. 
On the other hand if you run near flat out your wanted signal (along
with the unwanted harmonics ..) are way above soundcard input amp &
mixer noise, induced magnetic noise due to the unscreened transformer,
Noise picked up internally in the PC etc.

This is why I suspect that realworld results will in fact be better at
the hotter levels.

Visible waterfall ghosts can be resolved by setting your waterfall
dynamic range and sensitivity appropriately 


73
Brendan EI6IZ 

-- 
Don‘t complain. Nobody will understand. Or care. And certainly don‘t try
to fix the situation yourself. It‘s dangerous. Leave it to a highly
untrained, unqualified, expendable professional.