[Elecraft] KPA500

[Don Wilhelm]

Kurt,

Have you set the drive power level as indicated on page 9 of the KPA500 
manual?
After setting the drive power level, run the KPA500 at full power output 
and then adjust the ALC Threshold as indicated on page 10 of the manual.

If you are not driving the KPA500 to full output, you should see no 
change when adjusting the ALC Threshold.  Remember that the ALC signal 
is communicated back to the driving transceiver telling it to reduce its 
power output.  If you are using an early K3, has the mod for handling 
negative going ALC been installed?  Have you set the K3 EXT ALC menu 
parameter as indicated on page 27 of the K3 manual?

It is best to make those adjustments into a dummy load capable of 
handling 500 watts or more.  If you do not have a suitable dummy load, 
use whichever antenna provides you with a low SWR - the closer to SWR=1 
the better the results of your settings.

73,
Don W3FPR

On 10/29/2011 11:23 AM, walter renner wrote:
> I have KPA500 #429, and I really love the amp, but have been confused by the ALC threshold settings.
>
> Maybe someone on  this list can help me with a question I have concerning what it operation.
>
> The ALC settings are from 0 to 210, and I find that it has no effect on power out regardless of where I set ALC.
> The power out remains the same whatever the settings.  Nothing changes from 0 to 210 on power out. Any ideas setting has the least effect on
> power out or what setting has the most effect.
>
>
> Kurt    K0ARO
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