OK so I get up this morning, look at the Cincinnati slave and see 3AM but it's sunny outside! The homemade master is dead...It was built out of an "atomix" clock a friend got from Wal mart and had been dropped, I pulled the quartz movement out and removed all hands, attatching a disk with a slot cut in it to rotate on the second hand. The hour hand was redesigned with another disk and phototransistors and LEDs are mounted on both sides of the disks so the slot allows light through for about two seconds, triggering the relay sending 24V to the slaves. The quartz movement was of the self -correcting type to nist signal. Polarity reversal was used for correction. This system worked very well, and with battery backup the clocks ran for weeks without power after the hurricanes. As a fix I put in another quartz movement from a clock from the garbage. I wonder if anyone has devised a way to use a computer as a master clock, or made a homemade decoder to set their clock from the radio signal? It was nice to have accurate clocks here, but I would like something more robust than a cheap quartz movement as the master. The box the "master" is in has a clock on it as well, but it's just a slave clock which I guess is the "pilot" clock. Finding a real master is almost impossible so building one has worked for me.