At 11/23/2006 09:29, you wrote: >Bob, > >I would never think of using the 60 Hz power line to synchronize the clock >on a mountaintop repeater, since the power gets interrupted on a fairly >regular basis- usually due to the overhead lines touching due to wind >galloping, or a tree branch falling across the lines. Once the power is >interrupted, the time is in error and must be reset.
Not if the 60 Hz reference is backed up by the typical Dallas clock. >Cost-effectiveness in my book is based on not just the amount of time, >energy, and materials it takes to incorporate the modification, but also >whether it eliminates a trip to the site. Since most controllers that I am >familiar with run on DC power, the modification to add a 60 Hz synchronizing >signal is not a trivial exercise. I'm not suggesting that one modify an existing controller, but rather that the controller manufacturers incorporate this feature into future designs. The hardware required to implement this feature would be quite inexpensive compared to the GPS option. None of my sites have internet connectivity, so the NTP server option is not for me, nor would I be able to hang a GPS antenna outside the building without paying for the extra antenna slot. I suspect many others are in the same boat. >I've already breadboarded a "time hack unit" which marries a WWV receiver to >a tone decoder. At the beginning of each hour, WWV broadcasts 800 ms of a >1500 Hz tone. I have a simple tone detector set to key the repeater when it I once tried to pick up the 10 MHz WWV signal from one of my sites. No way - far too much processor noise in the building. Bob NO6B
