[UK-CONTEST] Power Limitations

[Ray Hills]

Bob (HGN),

When in employment, one of my responsibilities was the procurement of 
transmitting antennas for the IBA high power UHF TV sites.  These were 
custom built to a pretty detailed template (impedance, HRP, VRP) and were 
all measured on a calibrated test range before acceptance.  Even in those 
circumstances the measurements were subject to something like +/- 0.5 dB 
accuracy.  I doubt that the manufacturers of antennas for amateur use 
achieve anywhere near that accuracy.  Certainly there is one source which, I 
have been told, relies solely on computer modelling without any practical 
verification.  After all, 1dB is 10% of the power.

For any amateur, accurate measurement of power is readily achieved. 
Measurement of ERP is another story.

Ray G3HRH