[Elecraft] K3 on JT-65, ALC varies widely

[Don Wilhelm]

Brian,

Try this -- set the K3 LINE in gain to somewhere near mid-range, and 
then adjust the soundcard "speaker" slider to give you close to the 4 
ALC bars with the 5th bar flashing.  Refine that level with slight 
adjustments to the LINE in gain.

You can use TX TEST while making those adjustments which will not 
transmit any RF.

Adjust the desired power output with the power knob.

If you do not achieve the required number of ALC bars, the K3 will 
"power hunt" causing significant fluctuations in the output power.

There seems to be a greater number of questions about this "problem" for 
users of "JT" software than for other soundcard data modes.  I don't 
know why because the "JT" software should be no different than any other 
soundcard data mode.  Perhaps the user is trying to follow the 
recommendations in the JT mode instructions (I have not looked at them), 
but typically data mode instructions are for non-Elecraft tranceivers 
and say that the user should set the power to maximum and use the 
soundcard audio to adjust the power level.  That does not work with 
Elecraft gear which controls power differently than other amateur 
transceivers.  For Elecraft transceivers, adjust the audio level as 
specified and adjust the desired power with the power knob.  I cannot 
stress this fact enough.

73,
Don W3FPR

On 4/16/2017 9:19 PM, Brian Hunt wrote:
>   Don't see a problem with making minor adjustments of the Line In gain during the first transmission. When I adjust the level using the WSJT TUNE button I usually see the wild fluctuations mentioned. A small "tweak" to the gain will set right.