[AMRadio] Who Sets the AM Window Frequencies?

[Mike Duke, K5XU]

I'm just curious to know about how the current AM window frequencies were 
determined.

The one for 15 meters appears to have drifted up and down the band over 
several years.

I recall it being 21.330 one year, then 21.390, 21.415, 21.430, and now 
apparently 21.425.

I'm delighted to see the recent attempts at activity on 15 meters, and will 
make additional comments relative to that band later.

Mike Duke, K5XU