[time-nuts] How to measure Allan Deviation?

[John Ackermann N8UR]

Dr Bruce Griffiths said the following on 10/22/2006 07:19 PM:

> An inexpensive modern time interval counter with a power dissipation of 
> less than 10 watts and a resolution comparable to the 5370 would be 
> useful for such comparisons especially if the experiment lasts several 
> months.

I don't usually use the 5370 for long-term measurements, as it does make
a very noticeable amount of heat.  Since the long term averages don't
really need super resolution, I find that an HP 5334 counter, which has
2ns resolution and dissipates far less heat, works well.

My current experiment is using a 5334 along with a GPIB-controlled coax
switch (forget the HP number right now) to do 100 second averages of six
combinations (CS1-GPS, CS2-GPS, RB1-GPS, CS2-CS1, RB1-CS1, and RB1-CS2)
so I end up with a tau of 600 seconds and ~200ps resolution with the 100
sample average.

John