From: Phil.Kane@nov.shmovz.ka.pop   
      
   On Wed, 11 Nov 2015 10:51:48 -0800 (PST), hancock4@bbs.cpcn.com wrote:   
      
   >> Sounds to me like a voting receiver/remote transmitter system of that   
   >> vintage.  I got the "nickel guided tour" of Command Center in November   
   >> 1978 but didn't take notice of the dispatch console.   
   >   
   >Could you explain how that worked?   
      
   Be glad to.  Each Division had its own channel used throughout the   
   subway system.  The simplest radio system had transceivers   
   (transmitter-receiver combinations) at several sites, all using the   
   same channel.  The indicator lights would show which one was picking   
   up the signal, and the dispatcher would respond by using that   
   transceiver.   AFAIK that was the system in use for decades.  A more   
   sophisticated system would do that selection electronically based on   
   the strength of the signals received at several receivers, determine   
   the strongest one, and lock out the others, thus "voting" for the site   
   to be used.  This is the most common "voting system" today.   
      
   This works for both analog and digital systems, and is the basis of   
   cellular systems which use a group of low-coverage channels and can   
   use the same channel at multiple sites for separate communications. My   
   engineering firm designs all such systems for the public safety and   
   other land-mobile industries.   
      
   Philip M. Kane   P E / Esq.   
   VP - General Counsel & Engineering Manager   
   CSI Telecommunications Inc.- Consulting Engineers   
   San Francisco, CA - Beaverton, OR   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)