btw, another interesting thing about radio clocks that I have appreciated, is the perfect accuracy of predictions of satellites, ISS and Iridium flares in the website
www.heavens-above.com
Especially if you have a group of people around you, just set the alarm at the beginning of the predicted minute, and the sound of it makes them look up in full alert. Then, the iridium flare happens at the predicted second, at the area of sky which you have previously indicated with your green laser pointer.
Impressive!
Sparta Astronomy Association / Observations Coordinator
International Occultation Timing Association / European Section,
www.iota-es.de/
  