[Elecraft] OT-Wattmeter Errors

[Ron D'Eau Claire]

This discussion always begs the question, "How much accuracy is useful?"

The answer is "not much at all". 

Even when pushing the "legal limit" (which ranges from 50 watts to 1.5 kW
here in the USA, depending upon the frequency) the U.S. FCC rules say "not
to exceed". 

Since a 2:1 power change is detectable on the air only under extremely
stable signal conditions, it's easy to ensure one is within compliance with
the rules even with a somewhat questionable meter without compromising one's
on-air signal strength.

Bottom line: Those who understand the significance of power measurement
accuracy won't bother to pay for extremely accurate power meters for normal
Ham station work, and the popular meters on the Ham market reflect that. 

Even in testing for U.S. FCC compliance to relicense commercial
transmitters, my "Bird" was only as good as the FCC engineer's "Bird". If
they disagreed, no matter how many current inspection/calibration stickers I
had on mine, guess who was "right" by definition? 

That never became an issue because the FCC engineers, being engineers,
understood the variation one can expect and the absurdity of expecting
perfect agreement between two "good" meters - even "Birds".  

Ron AC7AC