[time-nuts] Z3805A/58503A time receiver : 2 questions

[SAIDJACK at aol.com]

Hello Claude,
 
that gap is a classic crystal jump. It could be caused by the crystal  
changing frequency by itself, or by being hit with e.g. gamma particles etc.  
Could also have been instigated by vibration or shock to the unit.
 
You should be seeing 6+ sats at all times though, your plot shows you  
sometimes seem to see 2 or 3 sats only? Maybe a better antenna position would  
help the stability of that unit.
 
Nothing to worry about if it doesn't happen regularly. Enjoy,
 
bye,
Said
 
 
In a message dated 2/27/2013 15:18:51 Pacific Standard Time,  
labtf1 at yahoo.fr writes:

Hello,

This is my first message here although I read this  list for a few weeks.

I bought a Z3805A/58503A frequency  receiver  and I didn't notice on the 
pictures that the model number was  not  written on the front panel. It's not 
important but is there a reason  for that, if you know ?
The item :  http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=251226027893  


I log some parameters of the receiver and today I notice a "gap"  in the 
frequency.

Picture :  http://uppix.net/e/2/4/cf39ac772e5a69fc616f5cf30f208.png

I have a  Rubidium and I measure it's frequency with a 5334B counter locked 
to the GPS,  and I can see the "gap" too  :
http://uppix.net/f/b/a/d86c2737ad135264e4a2b78e503d5.png
measurements  are with Gate Time of 10s, 60s and 100s, 


Do you know why this  happens and how to prevent this behaviour ?

Thanks for yours advices  


Claude