[time-nuts] Time syncing WiFi routers using FM radio

Hal Murray hmurray at megapathdsl.net
Thu Nov 12 03:04:28 EST 2015

kb8tq at n1k.org said:
> For time sync, broadcast signals are a pretty well studied topic. Sync
> signals from TV stations are a much better  ...

Many years ago, I think it was late '70s, a friend showed me a blurb from 
NBS.  They were distributing time by piggybacking on NBC's signal.  NBC had 
atomic clocks at their headquarters and a collection of links from the phone 
company running to all their stations.  The stations locked on to the 
upstream signal.  So the whole system ran in lock step give or take some 
propagation delay.  That was needed so they could switch between local and 
network signals without trashing the picture.  That was long before frame 

I think it was HP that measured the signal in the Silicon Valley area.  NBS 
published and distributed the offset.

Does anybody remember that booklet?  Did I get the story reasonably accurate?

These are my opinions.  I hate spam.

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