[Elecraft] KPA 1500 efficiency

[Ignacy]

This is normal from theory. Input power increase as I*U. Output power
increases as I*I*R. So at half input power one quarter output power. At 1/4
input power 1/16 output power.  

Two ways around, none implemented in KPA1500. Change transformer windings
like in  KX3, which is harder to do at high power. Lower the voltage as in
Expert amps. 

In old times, my 20A power supply to a 100W rig broke. I only had 5 A
supply. Was good for 5W. But after adjusting with tuner for a max power, the
output was 25 W. The tuner acted like a transformer. 

Ignacy, NO9E


 



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