[time-nuts] LTE-Lite module

EWKehren at aol.com EWKehren at aol.com
Mon Oct 20 19:01:54 EDT 2014


Allow me to clarify.
I started out with 7 MV 89 one of it a total loss. The remaining 6 after 3  
month +  burn in show better than 1 E-11 aging per day, 2 closer to 5 E-12. 
 Only two have been tested for ADEV and are close to 1 E-12,  2X not 10  X.
Bert Kehren
 
 
In a message dated 10/20/2014 5:58:37 P.M. Eastern Daylight Time,  
kb8tq at n1k.org writes:

Hi

The  problem is that there are no “magic coefficients”. What you run 
depends very  much on the exact OCXO you have, the environment you run it in, and 
the result  you are after. 

For instance, Bert is after frequency stability. Tom is  after the right 
time. Each of them will have very different coefficients for  the same 
oscillator. 

My Morion OCXO has a floor of 2x10^-12, Bert has  some that are 10X better 
than that (maybe). His coefficients and mine will be  very different. 

I had an antenna outdoors. It got many sat’s all the  time. Now I have one 
indoors. It’s not getting lots of sats all the time. My  old coefficients 
are not going to be my new coefficients. 

No magic  bullet, you have to do the work. 

Bob

> On Oct 20, 2014, at  1:20 PM, Brian Lloyd <brian at lloyd.aero> wrote:
> 
> On Mon,  Oct 20, 2014 at 6:48 AM, Bob Camp <kb8tq at n1k.org> wrote:
>  
>> Hi
>> 
>> We tend to focus on this or that  enhanced feature in a piece of code. It
’s
>> fun to talk about.  That’s not what keeps most designs from doing what 
they
>> should. By  focusing on this rather than the testing required, we set 
people
>>  up to fail. If you start off the project believing you mostly need  
fancy
>> code when you mostly need long term testing instead, you hit  a wall 
pretty
>> fast. Setting up for one is not at all the same as  setting up for the 
other.
>> 
> 
> Sounds to me like the  hardware and code are pretty straight-forward. The
> difference comes  from the terms and coefficients in the PLL loop filter 
and
> those need  to be optimized for each OCXO. There appear to be here a 
handful
> of  people who have a pretty good idea of what those coefficients should  
be
> for various well-known OCXOs out there.
> 
> So why not  do the GPSD hardware, software, and then provide the
> coefficients that  will get a handful of the more popular OCXOs available
> out there to  within a decade of optimum, certainly closer than what one
> would be  talking about by just bolting x-random OCXO onto an LTE-lite? I
>  suspect there would be a market in the time-nut world for such a  
critter.
> 
> -- 
> Brian Lloyd
> Lloyd  Aviation
> 706 Flightline Drive
> Spring Branch, TX 78070
>  brian at lloyd.aero
> +1.210.802-8FLY (1.210.802-8359)
>  _______________________________________________
> time-nuts mailing list  -- time-nuts at febo.com
> To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the  instructions  there.

_______________________________________________
time-nuts  mailing list -- time-nuts at febo.com
To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the  instructions there.



More information about the time-nuts mailing list