[time-nuts] Cesium Beam Lifetime

[SAIDJACK at aol.com]

Hello guys,
 
I got my FTS4050 Cesium Reference, and have it up and running. It  works 
quite well.
 
The Beam current reads 1.8V (I guess this means 1.8mA?), and Zeeman works.  I 
am now fine-tuning with GPS.
 
Some questions I had:
 
  * Can I read the remaining lifetime of the Cs tube out of the  beam-current 
somehow?
 
  * Should I reduce the Beam current once the unit is locked to  reduce Cs 
consumption as much as possible?
 
   * Should I only run it when doing tests (for a day or two),  then shut it 
off, or is it less stressful for the tube to run continuously? I  read that it 
may be difficult to get a lock on an old tube, but that it  just runs once a 
lock is achieved?
 
   * It seems this is the same tube sold by Symmetricom as their  replacement 
tube? Does anyone know how much $$ it costs to get a replacement  tube?
 
   * Is there any way to check how much lifetime operation this  unit has 
seen?
 
I am hoping to get at least 2-3 years out of this unit, and would love  to 
hear your suggestions about how to run it best to achieve this.
 
Lastly, I am looking for a cheap counter that can do 11 or 12 digits  
accuracy in a 1s intervall (I think the 53132A or SR620 can do it, but they are  
quite expensive). Any suggestions? 
 
Thanks in advance!
Said