[mythtv-users] Electrical power in my cable line? Is that bad?

David Brodbeck gull at gull.us
Fri Sep 7 16:27:45 UTC 2007


On Sep 7, 2007, at 8:10 AM, Brian Wood wrote:
> Precisely. Some B/W systems actually used the AC power line for a
> frame-rate standard.

Many surveillance camera systems *still* do.  Some simple matrix and  
sequencing systems, used to record multiple cameras on the same tape,  
require all cameras to be in sync.  Since the cameras run off 24 VAC,  
it's easier and cheaper to simply make sure the power supplies are  
all phased the same than it is to run the extra coax that would be  
needed to genlock everything together.





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