[Elecraft] Tips on setting transmit drive for PSK31

[Wes Stewart]

--- On Thu, 9/3/09, Don Wilhelm <w3fpr at embarqmail.com> wrote:

From: Don Wilhelm <w3fpr at embarqmail.com>
Subject: Re: [Elecraft] Tips on setting transmit drive for PSK31
To: "Doug Person" <doug at northroutt.net>
Cc: "elecraft at mailman.qth.net" <Elecraft at mailman.qth.net>
Date: Thursday, September 3, 2009, 4:06 PM

Doug,

Do not use the power output as an indication for mic drive on data modes 
(PSK31 for example).
The proper indicator is the "ALC" bargraph - adjust the audio input for 
4 bars with an occasional flicker of the 5th bar.

At that level, it is not an indication of ALC action nor compression.  
The ALC does not start until the 5th or 6th bar is illuminated - the 
lower 4 bars are an indicator of the audio level (sort of like a Vu meter).

If you set the audio drive too low, the K3 will attempt to develop more 
power to maintain the power output level you have chosen - that is the 
reason things seem so 'touchy'.

73,
Don W3FPR
Don,

I'm curious about your statement that "the K3 will attempt to develop more power to maintain the power output level you have chosen" -

Since PSK is an audio driven mode with a varying amplitude component,  linearity is very important.  What you are suggesting is that the K3 is highly non-linear and has infinite gain, i.e. it puts out X watts regardless of drive.

I know that you don't mean that, so could you clarify?

Wes  N7WS