[Brian R Pateman]

Very good critique of the calibration process. As an Instrument Engineer with over 35 years experience I am always surprised at the tendency to rely on a digital readout with loads of numbers after the decimal point as gospel.

For the sort of work most of us do on our vintage wirelesses, televisions, audio equipment etc, the standard industrial +/- 2% is more than adequate.

Those of us who restore vintage test equipment may require something better for calibrating back to "As Built" standards. It's a case of horses for courses.