Hi,
There are LF receivers available commercially today. See links below for one
vendor.
https://www.meinbergglobal.com/english/products/pci-express-dcf77-clock.htm
and even an USB version for the NIST signal.
https://www.meinbergglobal.com/english/products/usb-wwvb-clock.htm
And there see
Some stats in historic NTP surveys show that WWV and WWVB based refclocks
were relevant 20+ years ago:
1997 - Mills survey - 47 GPS and GOES vs 74 WWV and WWVB.
1999 - Minar MIT survey - 129 GPS and GOES vs 24 WWV and WWVB.
In those two years it is pretty obvious the world was swinging from LF a
