[Elecraft] K3 psk D splater

[David Moes]

Thanks Geoff

Understood. I have already shortened the leads quite a bit. and made a 
decent change in the voltage drop cant remember the difference.

Last night I was also able to make some tests (before the lead length 
change) using the K3 into a dummy and the second reciever with a very 
short antenna and DIGIPAN

My signal on PSK D looked great right up to full power. so I think I 
have everyting right and shouldn't have worried about what the other guy 
had said. The reason it had me going was that having worked PSK31 for 
many years using my old rig an then the K3 using DATA A I dont think Ive 
had any complaints for a long time. and on the first QSO I had with 
PSK-D someone complained. Murphy s law I guess.



David Moes
VE3DVY

PS sorry that you are getting this twice Geoff initially I sent to wrong 
address   I intended to post to the list


On 5/31/2012 10:52 AM, Geoffrey Mackenzie-Kennedy wrote:
> Hello David,
>
> If a PSK signal is generated in an early stage of a transmitter (or is 
> fed into an input of a transmitter), then all of the transmitter's 
> stages which follow should be "linear" to keep the signal clean.  In 
> the case of the basic type of PSK 31.25 signal consisting of a single 
> tone, whose phase is changed by 180 degrees, the change of phase 
> results in sidebands spaced 31.25 kHz each side of the main signal.  
> If the transmitter's stages which follow are not adequately linear, 
> then IMD products could create "splatter".
>
> In the case of solid state linear amplifiers, especially those using a 
> "12 V" DC supply, to prevent poor linearity it is necessary to use a 
> DC supply and interconnecting cables/ connectors which do not allow 
> the supply voltage to "sag" with increasing current draw.  I note that 
> you said that there is almost a difference of one volt between 25W and 
> 100W key down.
>
> 73,
>
> Geoff
> LX2AO
>
>
> On May 30, 2012 at 3:13 PM, David Moes VE3DVY wrote:
>
>
>> Question, What can cause splatter when using PSK-D  I had the power
>> dialed to  25W so I certainly wasn.t running to much power,  and just
>> to be sure that I was actually using PSK -d I had pulled the audio
>> line in/out from the K3. Am I missing something?
>
>