Hello, I've finally become successful in my long quest to have a working frequency standard. Here's the all-integrated unit I just finished putting together: http://imgur.com/a/IzROb Left LED = power Mid LED = phase lock indicator Right LED = unused. Was supposed to be PPS blinker, but this unit doesn't seem to output PPS :/ It puts out 10MHz @ about 10dBm. Uses about 18W when running, and gets quite hot! Since I couldn't find a decent high current 15V regulator @ Fry's, I just used a high gain (hfe min = 500) 80W/4A NPN and a 16V zener reference with a 20mA quiescent current. The regulated ~15.5V feeds the secondary 5V regulator, which is a normal 7805. The lock LED was a little tricky. The lock output from the unit is active-low (GND), but in the unlocked state it hovers around 2.5V output. I had to use a 22k pull-up (to +5V) resistor to eliminate glow from the indicator LED, while not taking too much current out of that weak pin when it's active (low). You can do fancier things with a pair of transistors, but given this is all rats nest wiring, that's too complicated. A single resistor works just fine! The mounting screws may seem overkill, but they serve the purpose of heat-sinking the rubidium unit to the aluminum chassis. The +15V supply output during the high-current warm-up period is not pretty. Quite the ripple is visible, but it does not seem to affect the unit at all. Once lock kicks in the +15V bus current draw drops off quite a bit. 60Hz harmonics are not a problem in the output, measuring about -73dBc. It's not the best, but it's good enough for my purposes! Using this I can now calibrate all the signal sources and spectrum analyzers for frequency accuracy! Yaaaaay! :) --Bart