[volt-nuts] Traveling Standards

[Andreas Jahn]

> Andreas mentioned the lm339.  One candidate I am considering is the
> lm119ah.

not LM339 (it is a comparator) but the LM399 is a heated reference.

really LM119AH? or LM129AH (I cannot find a reference when looking for 
LM119)

And the LM129AH has a tempco of around 6 ppm/K.
so you will have either to heat it or to monitor the temperature exactly.

But consider: when you maintain only one reference you are the happy man 
with one clock.
And you will never mention when the reference will drift by shipping.
I would maintain at least 4 equal references. Shipping only one at a time.
And comparing to the other 3 local references before and after shipment.

With best regards

Andreas