Has anyone hacked the large GE digital clocks that were designed to connect to a master clock using ZigBee networking? These are offered on eBay at varying prices, however the master clock is no longer available or is quite expensive when it can be found. There also seems to be no technical data available on-line. I have one that I run in stand-alone mode but I'd like to improve the accuracy to avoid periodic resetting. I suspect that because these units are supposed to be regularly updated from the master clock that their internal oscillator either wasn't tweaked at the factory or isn't that stable to begin with. I haven't yet opened it up to see whether adjustment of the internal oscillator is possible. Ideally, I'd like to add a more stable timebase, tie it to a 10 MHz GPSDO or PPS source or figure out a way to update it over ZigBee. Any suggestions would be appreciated. Fred Bray