[time-nuts] ways to make a HP 10811 better

ws at Yahoo warrensjmail-one at yahoo.com
Tue Sep 20 22:55:38 UTC 2011

> This is mentioned ( that the 10811 is not always operated at it's exact 
> turn over temperature) in the HPJ article on the 10811.
> (Required reading for anyone playing with 10811's).
> Rick Karlquist N6RK
Yes it does and it also says that is to save testing time and make it field 
repairable etc.
Problem is that now the resulting freq sensitivity can be as high as 1.5e-8 
/deg (at the xtral)
This is Many decades greater than what it is at the true turn over point.
Since I try and remove any measurable freq change,
and 1e-12 freq change is easy enough  to measure (in >= 0.1 sec),
Call me nuts, but seems worth while to spend a few extra minutes of  nut 
time to find and set the turn over temp to be exact on so that any small 
oven drift no longer effects the freq.

One big different is they need to make all of them meet a min spec,
and I just want to find one best one that is decades better than their worse 
case specs.

Next experiment needed is to see if anything can be made better by changing 
the power split between the two heater transistor.
Interesting enough, they made the point it was never re-tested after they 
got out of protype.

I changed the subject title so as not to add more noise to the latter OT gas 
and speed postings.
For me, don't need the gas and OIL or even a basement full of metal and 
mercury, A simple outer oven works so much better.


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