[Elecraft] K3 Harmonic Distortion

[Berni G0IDA]

Thanks everyone for the replies.

I just would like to put this thread back onto its tracks..... The 
problem is with CW (although SSB does suffer too) and the main problem 
is that I can hear the 3rd harmonic which when mixed with the 
fundamental makes a rough note on CW especially when tuning away going 
up in frequency.

I only used the waterfall program to confirm and to see at which 
harmonic it occurred and line levels, AGC, PC cards etc...etc... have no 
baring on this as I'm not measuring anything, just confirming that it is 
there.

I compared 2 K3s and both had the same effect.

I'm using a Hiel headset to listen to CW it is also noticeable on the 
main speaker but less so due to its design.

When confirming on the waterfall and indeed with my ears the rig is at 
default setting & no amount of tweaking helps. Even with 1KHz of 
filtering a 3rd harmonic is present.

K9YC:
1) Yes
2) Line level is irrelevant as I'm just confirming that it is there and 
at which harmonic so as to give feedback to the reflector.
3) as above.

N4LQ:
I agree with you, nothing seems to help and I've never had this with the 
FT1000MP or my recent Mk v.

W4TV:
I envy the K3 you have.... as there is 3rd product distortion and never 
had this on any other rig... could there be a "bad batch" or K3s?
Just like to re-iterate that the thread is not about how to set up your 
PC/LINE OUT or IN not to get distortion, it is about 3rd harmonic 
distortion present on the headphone socket and speaker with or without 
default settings!

Jim:
PSK + RTTY might have its own problems & its not part of my discussion, 
I'm trying to concentrate this thread on just one mode CW where this 
problem is significant as at times it is unpleasant to listen to. SSB 
also has this unpleasant distortion.

There is one option a friend suggested.... wait until I get older and 
the hearing drops off in frequency.... at the moment it seems the only 
option..hi..hi..hi..

73s

Berni
G0IDA




Jim Brown wrote:
> On Mon, 01 Sep 2008 14:30:45 +0100, Berni G0IDA wrote:
>
>   
>> I hope there is a cure for this as it's frustrating listening to CW with 
>> this sort of distortion.
>>     
>
> There are three things you should do. 
>
> 1) Make sure that the AGC is on, and that the CONFIG AGC settings are at the 
> defaults.  
>
> 2) Reduce the LINEOUT GAIN (on the CONFIG menu) to a value less than about 4. 
> This prevents distortion that could occur in the output transformer.
>
> 3) Adjust the input gain of your computer so that you have enough signal for 
> the decoder to function, but not enough to cause distortion.
>
> This should correct any problems.
>
> 73,
>
> Jim K9YC
>
>
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