[time-nuts] Looking for info about first true radio controlled clock

[michaelalombardi at comcast.net]

Thanks very much for the replies so far.  I should have been more clear.  I am looking for the first radio controlled clock 
that received a digital time code from a radio transmitter.  Not a telegraphic time code (those date back to around 
1920), not a IRIG system, not a slave/master clock system (those date back to the beginning of electric clocks), but 
a digital time code broadcast by radio. 

As far as I know, the first digital time code broadcast by radio was the 36-bit NASA code on WWV which began in 1960. 

By the definition above, the first true radio controlled clock I know of was the Develco 3391 (around 1968 or 69). It 
received the time code from WWVB on 60 kHz.  BTW - WWVB certainly wasn't ideal, but it was widely used by the power 
industry in the pre-GPS days.  It was also widely used to time seismic events. 

Would be interested to know of anything earlier that meets the criteria of the above definition.  Would also be 
interested in hearing from anyone who has seen or owns a Develco, and could send a picture. 

Thanks! 

Mike 



Hi 

The power people have a tough time with RF based timing. Their equipment 
makes picking up anything below VHF difficult at the "point of use". Their 
traditional solutions were more wire line oriented. GPS was the first RF 
system to really get them interested. There's a FCS paper on it from the 
80's(?). 

Closer to the original topic. The IRIG stuff dates to 1956 according to 
Wikipedia. There were similar setups running around when IRIG was being 
worked on. The whole reason for doing it was the proliferation of 
incompatible gear. There must be mid 1950's gear around that did one sort of 
time code or another. 

If your definition of time code is loose enough, the electro mechanical 
master / slave clock could be considered a time code transmitter and 
receiver. That puts you back past 1900. Pretty loose definition though. 

Bob