[Elecraft] KPA500 - linear power supply

[ac5p at sbcglobal.net]

I know this is a real long shot, BUT, do any of you fortunate folks who already use the KPA500 have the instrument or capability to measure the KVA demand and power factor or phase angle of the AC input to the amp under full load output?   Just curious about  this and the overall efficiency of the unit.   Just saw the inside photos yesterday and that big current transformer is a beauty.  
 
Mike, AC5P