[time-nuts] Spectracom 8170 -> SWCC clock

Jim Hickstein jxh at jxh.com
Sat Jan 21 21:03:30 EST 2012


Exellent intel, thanks! The face has a penciled legend "I C Depot" which I suppose stands for Illinois Central, the railroad. But I would think mine works the same way as all the others.  The coil holds down a follower against a cam, so the :59:59 thing makes sense. I will check this out by just doing it with a button at first.

On Jan 21, 2012, at 9:25, Brucekareen at aol.com wrote:

> Jim,
> 
> If your Western Union clock is similar to the type used in broadcasting,  
> you might want a setting pulse that starts at 59:59 and ends at 00:00 .   The 
> reason is that at 59:59 the magnet pulls the second hand to the 12 o'clock  
> position and releases it on the hour.  The one-second difference might seem 
> trivial, but it's actually about three words for an announcer beginning a  
> network broadcast.
> 
> When Western Union got out of the clock business in the late 1970s  
> (following a technician strike where the master clocks were ignored and service  
> deteriorated)  the company I worked for purchased the clock installation  from 
> Western Union (for $75 per clock as I remember) and we installed a digital  
> master system.  The Western Union clocks were all connected in series and  
> driven as a constant-current teletype type loop.  We had wire-wrap  logic 
> panels associated with the digital master time system.  Signals for  the W. U. 
> clocks, for alerting control rooms before newscasts, starting  recordings, 
> etc., were implemented by simply adding chips, DIP  relays, 14/16-pin boards 
> with components such as timing capacitors,  and wire-wraping the underside 
> pins.  I/O was implemented with those  14 and 16-pin DIP connectors on one 
> end of ribbon cables -- the other  ends being terminated on barrier strips on 
> rack wall  panels.  
> 
> Bruce 
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