wrote in message
oups.com...
Then how come wall clocks based on WWVB work so well anywhere in CONUS?

They don't -- there are plenty of places in the U.S. where it takes a fair
amount of experimentation to get them to sync at all. Most of them 'listen'
in the wee hours of the morning when propagation tends to be better too. And
finally, even if they do only manage to sync up 'once in a while' (say every
week or two), they still perform much better than a typical wall clock.