[Elecraft] [KPA500] K3S/KPA500/KAT500 - Adjusting TX Power

[Kevin Stover, AC0H]

The difference is Data A mode.
In Data A mode ALC action doesn't start until the fifth bar is lit AFAIK 
it's been that way from the beginning.

With Elecraft rigs you don't control power out by adjusting audio level.
Adjust your sound card line out to 50%, or less, adjust your software to 
50% or less, adjust the K3(S) line-in. Fine tune the line-in level to 4 
bars steady and the 5th barely flickering. Once set don't fiddle with 
it. Adjust power out with ye olde power knob.

If the manual says 5-7 bars for digital modes it needs fixing.
Data A, AFSK, SSB (upper or lower running a digital mode)should all have 
zero ALC action. Been that way since PSK31 was new. On an Elecraft rig 
that means 4 with 5 flickering occasionally.


On 9/8/2017 4:35 PM, Wes Stewart wrote:
> I am often puzzled by some of this advice. The K3S manual on page 30 
> says among other things:
> 
> "While speaking into the microphone in a
> normal voice, adjust MIC for a peak ALC
> meter indication of about 5-7 bars (see below)".
> 
> Then regarding audio data modes it says on page 34:
> 
> "If you’re using an audio-shift transmit mode (LSB,
> USB, DATA A, or AFSK A), you’ll need to set
> the MIC level while watching the ALC meter.
> You can use the same procedure outlined for voice
> modes (pg. 30), except that speech compression
> should not be used."
> 
> So 5 to 7 bars seem to be indicated.  Where does the '4 solid, fifth 
> flashing come from'?
> 
> This is particularly questionable with constant amplitude modes, where 
> it doesn't matter whether there is ALC developed or not.
> 
> Maybe someone can enlighten me.
> 
> Wes  N7WS
> 
> 
> On 9/8/2017 5:36 AM, Don Wilhelm wrote:
>> Bret,
>>
>> This is a condition we call "Power Hunting", and it usually indicates 
>> that you do not have the audio level set correctly for Elecraft 
>> transceivers.
>>
>> Are you driving the audio to illuminate 4 bars on the K3S ALC meter 
>> with the 5th bar flashing?  You must operate Elecraft gear differently 
>> than other transceivers because of the closed loop system used for 
>> power control is different than the simplistic "control the drive 
>> level" system that other transceivers use.
>>
>> Ignore the internet (and WSJT-X) advice which tells you to adjust the 
>> power with the audio level and set the power to maximum.
>>
>> With Elecraft gear, set the audio as instructed in the manual and 
>> adjust the power with the POWER knob.
>>
>> 73,
>> Don W3FPR
> 
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-- 
R. Kevin Stover    AC0H
FISTS #11993
SKCC #215
NAQCC #3441
ARRL