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

[Michael Lombardi]

I'm trying to determine the first product that could automatically decode and display a digital time code.  Digital time codes were added to WWV in 1960 and WWVB in  1965.  This was before they were added to any satellite  signals, or before they were added to LF stations in Europe, such as DCF77.  Telegraphic time codes, of course, were around much earlier.

I currently think the first true radio controlled clock that decoded a digital time code was the Develco 3391, introduced around 1969.  It received WWVB signals and was used by the electric power industry.

Does anyone know of anything earlier?  Also, has anyone seen a Develco 3391 or have a good picture of one?

Any help would be appreciated.