HF propagation of WWV or WWVH is horrible compared to VLF propagation of WWVB at 60 kc. In this video the 5 mc WWV signal from Ft Collins, Colorado is being received in New Jersey. It was compared against a stable 5mc crystal source. You can see a shift of a few cycles per second over a few seconds. This is due to the movement up or down of the ionosphere at a substantial fraction of the speed of sound. I understand that it can be as bad as a part per million short term at some frequencies. The 10 mc and 15 mc broadcasts may be better or worse at various times of day.
I have spent many hours watching WWVB in the days when they had the old format. It was good to a part per billion except just before sunrise and just after sunset. Then it degraded to either + or -5 parts per billion for about 30 minutes. https://www.youtube.com/watch?v=nf9KWfS9QBs _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
