[Elecraft] K3 psk D splater

[Geoffrey Mackenzie-Kennedy]

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?