Glenn, What was the DC voltage at 100 watts keydown? It should be 12 volts or greater - more is better, 13+ is good.
If the voltage drops, the current will increase (and I believe the efficiency decreases) to maintain your 100 watt output level. More current, more heat.
An off center fed antenna may present a reasonable SWR, but SWR does not tell the whole tale. OCF antennas are infamous for RF-in-the-shack problems, so you might have some RF floating around to create 'strange happenings'.
73, Don W3FPR On 6/1/2014 1:06 AM, WA7SPY wrote:
I have had my KXPA100 for 5 months or so now. I have loaded the latest firmware Wayne sent out a few weeks ago for beta testing. My KXPA100 has the Automatic antenna tuner installed. I run the amp into a Carolina Windom 40 and the automatic antenna tuner works well using this antenna on all the bands except 160 meters of course. I normally don't operate on that band anyway. I was running the amp on 40 meters at 100 watts doing back to back rag chewing CW QSO's this evening. The amp shutdown and my KX3 display showed Hi PA current. The amp was very hot to the touch which makes me believe the amp had to shut down to protect the finals. The antenna SWR shows under 1.2. to 1. Is this normal behavior for the KXPA100?
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