[time-nuts] FA2 internal OCXO orientation sensitivity

[Bob kb8tq]

Hi

A lot depends on the source of the tip sensitivity. If it is acceleration then 
indeed vibration will get to you. It’s also possible that the sensitivity is due
to thermal issues. In that case, vibration will not be as big an issue.

Worst axis is about +/- 3 ppb so it could be from either source. 

Bob

> On Oct 14, 2019, at 5:45 PM, Didier Juges <shalimr9 at gmail.com> wrote:
> 
> If it is sensitive to orientation, it is probably also sensitive to
> vibrations, so mobile applications may be out of the question, depending on
> your needs.
> 
> Didier KO4BB
> 
> On Mon, Oct 7, 2019 at 2:00 AM Mark Sims <holrum at hotmail.com> wrote:
> 
>> The first time that I tried to set the FA2 internal oscillator frequency I
>> tilted the case so that the screen was facing down and the adjustment screw
>> was facing up.  I got it on frequency, but when I placed the unit with the
>> bottom of the case facing down the oscillator was 0.032 Hz off.  So I did
>> some more testing with the case in various orientations.  It looks like the
>> frequency is fairly insensitive to orientation except for tilt in the
>> front-back axis where it is around +/-1 milliHertz per 3 degrees of tilt
>> (which seems rather high to me).  If you are using the FA2 in a mobile
>> application pay close attention to the front/back tilt of the case.
>> 
>>   F:0010000000.001619430  bottom down
>>   F:0010000000.001687723
>>   F:0010000000.001946380
>>   F:0010000000.001902348
>>   F:0010000000.001692710
>>   F:0010000000.001663366
>>   F:0010000000.001712156
>>   F:0010000000.001760899
>>   F:0010000000.001590295
>>   F:0010000000.001648737
>> 
>>   F:0010000000.001922004 bottum up
>>   F:0010000000.002214679
>>   F:0010000000.002209653
>>   F:0010000000.002063463
>>   F:0010000000.001912133
>>   F:0010000000.002556087
>>   F:0010000000.002775519
>>   F:0010000000.002053697
>>   F:0010000000.002014587
>>   F:0010000000.001570725
>> 
>>   F:0010000000.033927950 screen down
>>   F:0010000000.033435257
>>   F:0010000000.032562128
>>   F:0010000000.032625399
>>   F:0010000000.032098574
>>   F:0010000000.032225335
>>   F:0010000000.032391257
>>   F:0010000000.032571790
>>   F:0010000000.032922928
>> 
>>   F:0009999999.971298357  screen up
>>   F:0009999999.967820455
>>   F:0009999999.967859533
>>   F:0009999999.967986393
>>   F:0009999999.967800925
>>   F:0009999999.967947314
>>   F:0009999999.968327835
>>   F:0009999999.968252960
>>   F:0009999999.968030373
>> 
>>   F:0009999999.998658455  left edge down
>>   F:0009999999.998985308
>>   F:0010000000.000419484
>>   F:0010000000.002063510
>>   F:0010000000.003292634
>>   F:0010000000.003956045
>> 
>>   F:0010000000.002448722  left edge up
>>   F:0010000000.002029197
>>   F:0010000000.001917045
>>   F:0010000000.001985357
>>   F:0010000000.002012571
>>   F:0010000000.001980588
>> 
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.