Re: wattage on k3 vs kpa500

Posted by ab2tc on Nov 24, 2011; 7:39pm
URL: http://elecraft.85.s1.nabble.com/wattage-on-k3-vs-kpa500-tp7026865p7029300.html

Hi,

Does the K3 have an antenna tuner and is it enabled? If it does, your readings may be entirely accurate. The K3 delivers 60 watts into the matched load it sees. The KPA500, however is on the unmatched side and sees 80W forward power and 20W reflected which is the 25% reflected power equivalent to a 3:1 SWR. I think you should be able to measure reflected power on the KPA500. And what is the SWR reported by the K3? The other possibility is that with a real antenna you have RF in the shack sufficiently strong to cause power measurements to vary along the transmission line.

AB2TC - Knut

RICHH wrote

Hi
  Maybe some one can answer this.   I set my k3 to 60 watts and measure 60 watts on my kpa500 meter with the amp in standby trnsmitting into a dummy load.  When I switch to an antenna with a 3:1 swr the k3 still says 60 watts but the kpa500 now reads  80 watts  with the amp still in standby.   So which is correct  or neither ?
Thanks Richard
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