ft
point taken. I'm just trying to explain that sometimes
123.45 is a valid freq. which flying at 370000' might interfere with local aerodromes which also use it. I recently saw a Notam
in Canada urging local airplaines not to use 123.45 because
it can be received at the west coast of England/Ireland!
They then must be flying at FL800 but there you go.
Rgds