[Elecraft] K3s meter

[Don Wilhelm]

All,

Guy is quite correct.  The K3 controls power very well, so if you have 
set the power knob to some particular power, that will be very close to 
the power you actually get.  There is normally no need to monitor it - 
as long as other conditions are followed.

The most common error for soundcard data modes is for hams who choose to 
follow the common internet advice to "set the power to maximum and 
control the power with the audio drive" - that does not work well with 
the K3, K3S, KX2 or KX3 (or the K2 for that matter).  Drive the Elecraft 
ALC meter as indicated in the manual - 5 to 7 bars for SSB and 4 bars 
solid with the 5th bar flickering for soundcard data modes.

Elecraft radios do not control power in the same way as other 
transceivers, so follow the instructions given for your Elecraft 
transceiver and first set the audio drive properly and control the power 
output with the power knob.  Failure to do that will result in what I 
call "power hunting" where the power output will vary significantly.

If I must elaborate on the "why" of all this, Elecraft radios control 
the power output in a closed loop - other amateur transceivers use an 
open loop "drive" control, commercial transceivers may use a closed loop 
system similar to Elecraft.  The power output is measured and the MCU 
compares that output with the power requested by the power knob.  If the 
actual power is less than requested, the drive will be increased to make 
the output equal to that requested.  So if the audio drive is not 
sufficient, yes power will be lower than the requested value and the 
transceiver will go to full possible drive (and excess power will be 
produced when the audio output is increased).

For those who are concerned about the ALC meter indication, the onset of 
ALC is at the 5th bar on the meter - the 4th bar is the "NO ALC" point 
for the K3 (KX3, KX2 and K3S).

For the K2, increase the audio until you have ALC indicated, and then 
back off the audio just enough that no bars are displayed.

The real key is to set the audio as instructed in the manual, and then 
control the power with the power knob.  That goes for voice modes as 
well as soundcard data modes.

73,
Don W3FPR


On 1/7/2017 1:51 PM, Guy Olinger K2AV wrote:
> Hi Richard,
>
> The issue with your request is that there is only **one** line of display
> "dots" on the display. The single line of dots is interpreted with the
> upper graticule in RX, and with the two lower graticules on TX.
>
> For what you want, there would need to be two rows of dots driven
> independently. Or there would need to be a front panel button to switch the
> meaning of the single row of dots. Ah, but we already have the button.
>
> Also, the change would require *both* firmware *and* changing out the
> display to create the **two** lines of dots on the display. Note that the
> graticules do not change. The display is not driven pixels like a
> smartphone display. Therefore it could not just be a new CONFIG: option in
> firmware. The request would almost certainly need to be implemented with a
> new transceiver.
>
> As it is, on voice if CMP and ALC is properly set, on a K3/K3S the power
> out is very predictable for a given PWR setting, more so for a K3/K3S than
> most. In any event, TX SSB with an amp, various stand-alone power meters
> deal more substantially with power out aspects.
>
> 73, Guy K2AV