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Take a look at NIST's propagation charts for WWVB. You can clearly see the US East Coast getting little signal at certain times during the day: https://www.nist
by jgrahamc 5y ago
Take a look at NIST's propagation charts for WWVB. You can clearly see the US East Coast getting little signal at certain times during the day: https://www.nist.gov/pml/time-and-frequency-division/radio-stations/wwvb/help-wwvb-radio-controlled-clocks https://www.nist.gov/pml/time-and-frequency-division/radio-s... You're actually getting the best coverage at about the same time my clock was hearing its first signal in 15 years.
- politelemon 5y agoWhy is the propagation different during different times of day? On that page, it says > WWVB radio controlled clocks should be able to work in most places in North America. The red areas on the coverage maps below show where a WWVB radio controlled clock should be able to synchronize. Note that the red area is largest at night, and smallest in the daytime (click on the map to see a larger image). For example, 0600 UTC is about midnight in the central United States.
- jgrahamc 5y agoWhy is the propagation different during different times of day? Welcome to the wonderful world of radio propagation. Different radio signals at different frequencies "bounce around" the world in different ways. LF (low frequency) which is where the WWVB beacon operates bounces off the ionosphere (refracts) and can bounce very long distances. But the bouncing depends on conditions in the ionosphere which are affected by day/night cycles and sun cycles. Start here for some information: http://rsgb.org/main/files/2012/10/Understanding_LF_and_HF_propagation.pdf http://rsgb.org/main/files/2012/10/Understanding_LF_and_HF_p...