On Sat, 2 Jun 2018, Chuck Guzis wrote:
So 200 and 800 are nice decimal multiples of 10. But
556 doesn't fit
that pattern--it's not a "nice' number, being the product of 4 and 139
and doesn't correspond to any computer-related characteristics that I
know of. It's not metric. So why 556 and not 400, 512 or 600?
Just a guess, but 556 kHz is 5 MHz divided by 9.
Christian