[Elecraft] Re: K3 Audio

[Jim Brown]

On Fri, 08 Aug 2008 21:56:41 +0200, Alexandr Kobranov wrote:

>last test to test possible AGC influence on ghost signals is here

When you turn off the AGC, you are likely to overload the audio 
system in any radio. The trace below is nothing more of less than 
harmonic distortion caused by the overload of an audio stage. Could 
be the K3, could be the sound card. 

http://www.ok1kei.org/K3_audio/line_out_agc_off_500Hz.JPG

>Without changing of soundcard input gain the same performed with 
>TS-850

>http://www.ok1kei.org/K3_audio/ts850_agc_off.JPG

The second trace shows that the audio system is not being 
overdriven. The difference could be nothing more than how levels are 
set or how much gain there is between the detector and the audio 
system. 

You've excited the audio system with a single frequency. If you 
excited it with broadband noise, as I did, you would also see the IM 
components of distortion. 

73,

Jim Brown K9YC