[Elecraft] KPA1500 Initial High Power Surge

Jim McCook w6ya at cox.net
Tue Dec 22 14:54:24 EST 2020


Thanks to K6XX for solving this problem with a huge power output surge 
on certain bands while driving with the K3.  With the proper drive level 
set on a new band the first dit would display a huge surge over 1900w, 
then settle down to normal over 2-3 seconds.  This would happen again if 
the drive from the K3 were readjusted even by 1 watt!  I know several 
others have had this problem.  Bob said the K3 should never transmit at 
or have CONFIG:TUN PWR set to 50w.  I didn't realize this before, since 
that probably caused my problem.

The solution is to redo the TX GAIN calibration.  I think that process 
is too vague in the K3 manual, since I'm a dummy with this stuff.  
Here's what I did with the K3 to solve the problem:

Set CONFIG:PWR SET to PER BAND
Set PWR control to 5w
Set CONFIG:TUN PWR to 5w
Hold TUNE - saw 5w
Repeated all with 50w settings - saw 50w
Immediately reset TUN PWR to 25w
Immediately reset PWR to 100w
Drive power settings for the KPA1500 were retained

I also went to the KPA1500 and adjusted WMTR ADJUST on each band to show 
close to my trusty Bird 43 values.  Again, do NOT transmit at 50w with 
the K3.

73, Jim W6YA


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