[time-nuts] Got 60HZ?

[Michael Poulos]

Recently I bought a Efratom Ru frequency standard from eBay and a 
frequency divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a 
1HZ output. Today I thought of a way to make a nice 60HZ so you can use 
a mains-powered clock for the display (using amplifier and transformer 
wired "backwards"). But, now you'll need 60HZ. A European has it easy 
with 50HZ as you use a BASIC Stamp or Arduino to divide the 100HZ 
output. But for 60HZ I came up with a solution:

You set up the Arduino to take the 10KHZ from the divider chip and 
program it to count off 83 pulses to flip an output. But wait! Unless 
you add a "leap count" every 3 flips of the output, it'll run fast. 
Assume at the start the Arduino output starts high then turns low:

(83+83+84+83+83+84)*20 = 10,000 pulses = one second
 H__L__H__L__H__L

Every output cycle and a half the voltage swing is a little over 1 
percent longer because of the leap count. This means that the distortion 
adds a slight inaccuracy, not enough to upset New Year's revelers. But 
if you want a better 60HZ, try using the 100KHZ:

(833+833+834+833+833+834)*20 = one second

You see where this is going with leap counts. The ultimate of course is 
one really good Arduino and (after a hex inverter to amplify it) take 
the straight 10MHZ and apply this leap count technique:

(83333+83333+83334+83333+83333+83334)*20 = one really accurately made 
60HZ = one nice second, just the thing for a Nixie clock. :)

Now, what is a good hex inverter to take the 10 million HZ of my 
rubidiom movement to feed a frequency divider chip (and later Arduino)? 
It needs to take the .5 of a volt sinewave and squarewave it and in a 
normal 14 pin DIP (breadboardable) package.