[time-nuts] HP 5335a opt 40 addendum

Magnus Danielson magnus at rubidium.dyndns.org
Wed Oct 22 07:56:35 UTC 2008

Dear Norm,

Norman J McSweyn wrote:
> Magnus,
> Thanks for the enlightenment!
> I modified the driver that NI has on their site. Works. Have been 
> manually setting the trigger levels on the front panel. Now know how to 
> use the -40 to do it.

Great! Happy to help!

> I'll further modify the driver in the AM.
> The manual I have doesn't have programming example 13.

I haven't looked in detail, but I *think* the HP5335A manual on the HP 
site is the same as I have, and then you should have all the details you 

> I take it that the instrument will trigger automatically when the 
> conditions are met?

Indeed it does.

> I'm comparing the 1pps output from an M12+t to the divided down 10MHz 
> out from a Thunderbolt.
> Next hurdle is to do something with the collected data.

Way to go!

You should learn to calculate Allan deviation and friends. Not to hard.
You should learn to estimate drift rate and subtract that from 
measurements, since that is often ignored and the drift rate will form a 
lower floor for longer measurement runs. This is an error which is 
either canceled by locking or by software.


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