303-499-7111 Atomic Clock - Colorado number
I knew that voice sounded familiar!
It is possible to pick that up on a shortwave radio. I used to listen to it 2 or 3 years ago, when my shortwave was still working, in order to find out interesting weather information and to set my clock right every so often when it was a few minutes off :p
I can't remember the frequencies correctly, but I want to say that they're...
5,000Hz
10,000Hz
15,000Hz
20,000Hz
Not necessarily broadcasting on all of the frequencies at one time. They change depending upon which has the best reception.
I think on every hour they broadcast all the information about the frequencies and the time station.
Just for a random little fun fact:
somewhere in-between 7,000Hz and 8,000Hz are some weird data noises and I always wondered what they were. It might be in the 7,700's or the 7,200-'s to 7,400's.