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Re: f/w 2.73/1.98 power calibration

Posted by Julian, G4ILO on Dec 15, 2008; 10:28am
URL: http://elecraft.85.s1.nabble.com/f-w-2-73-1-98-power-calibration-tp1651339p1657645.html

Richard Ferch wrote
It's more than just the power calibration. Even after calibrating power and
setting the requested power below 50W, with either 2.73/1.98 or 2.72/1.98
the power output on PSK31 (in DATA A) mode often exceeds the requested
power, which results in splatter. I have been having to constantly ride the
LINE IN and/or sound card output level controls in this weekend's PSK
contest to keep the power below 50W and PSK signal quality acceptable; I
have now switched back to 2.67/1.96 for the remainder of the contest.
I don't think it is anything to do with this revision. I first noticed this a few months ago, after one of the updates that made some changes to the ALC. Adjusting TXG VCE may be the answer, but the other change I made was to avoid tuning at 5.0 or 50W. The K3 recalibrates the power when you press TUNE at those exact power levels, and if it is looking into a mismatched (or varying, as you adjust the ATU) load then it mucks up the calibration.
Julian, G4ILO. K2 #392  K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com
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