[time-nuts] Spectracom 8170 -> SWCC clock

Brucekareen at aol.com Brucekareen at aol.com
Sat Jan 21 10:25:58 EST 2012


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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