[time-nuts] 10MHz LTE-Lite

paul swed paulswedb at gmail.com
Thu Nov 20 22:20:29 UTC 2014


David
I picked up the 20 and its working well. But the 10 saves you the divide by
2. I know thats quite minor.
Several comments.
Said mentioned that it should be in a bix to prevent air currents.
Absolutely. Though my fix is a pair of heavy socks. It tends to behave like
the 3801 and KS-36... But on occasion does swim slowly forward or backward,
not sure it actually swims past a total cycle. I am comapring that to the 2
X 10 MHz references from above. Granted the LTE is at 20 MHz.There does not
appear to be any constant drift.
My unit settled easily within 1 hour after the sock insulation. I may step
up to a cardboard box real soon now.
I am using Putty it works absolutely as well as anything else. Especially
since you can only listen to the LTE. Nothing else in the ublox works but
the debug screen.
Hope that helps.
Regards
Paul
WB8TSL

On Thu, Nov 20, 2014 at 5:08 PM, S. Jackson via time-nuts <
time-nuts at febo.com> wrote:

> Hello Mike,
>
> attached is a 10MHz DIP-14 TCXO Phase Noise plot from a random  LTE-Lite
> unit.
>
> I had sent out a 20MHz typical phase noise plot some weeks ago, and
> comparing the two they are almost perfectly 6dB apart as would be expected
> from
> the 20log(n/m) relationship. There are variations from unit to unit of
> course,  but it does not seem like one version of the board or the other
> has
> advantages  in terms of phase noise.
>
> I had also sent out a superimposed plot of the 20MHz and the divide-by-2
> 10MHz output of the same board at that time, and again the relationship was
> almost perfectly 6dB lower at 10MHz versus 20MHz.
>
> While phase noise follows theory, it does seem that the DIP14 metal shield
> has a beneficial effect on the ADEV stability though. The plots we are
> getting  are pretty darn good, and I want to test more boards before I
> post any
> ADEV,  because its quite a bit better than our specification and I want to
> make sure  its real.
>
> The 10MHz DIP-14 boards do not have an isolating buffer like the 20MHz
> boards do, on these the TCXO drives the output directly, so one must be
> careful
>  to set the equipment to 1M Ohms input impedance or use a buffer
> externally,  which is what we did to measure the attached PN plot.
>
> Bye,
> Said
>
>
>
>
> In a message dated 11/20/2014 13:48:22 Pacific Standard Time,
> n1jez at burlingtontelecom.net writes:
>
> Hi  Said,
>
> Have you ever done a phase noise comparison of the 20 MHz TCXO  divided
> by 2 and the 10 MHz TCXO version?
>
> My unit has only been  powered for a few hours for initial tests. I'm
> using the uBlox U-Center  software version 8.12 for monitoring the GPS.
>
> Mike
>
> On 11/20/2014  3:32 PM, S. Jackson via time-nuts wrote:
> > Hello  everyone,
> >
> > after what must have been the longest thread in  T-nuts history its
> almost
> > all quiet today. I am going to take  advantage of that and  announce some
> > good news:
> >
> >  Its a miracle: the 10MHz DIP-14 TCXOs for the LTE-Lite came in weeks
> ahead
> > of schedule from the factory! And they work very  well.
> >
> > We will thus be shipping out the 10MHz LTE-Lite eval  boards in the  next
> > couple of working days. There are still a  number left for sale on Ebay
> > (search for "LTE Lite GPSDO"), so if you  were hesitant to get one due to
> the  long
> > lead-time, then now is  your chance.
> >
> > Also, after being in time nuts hands for almost a  week I am surprised
> > there are very few mails, questions, or comments  about the 20MHz boards,
>  and we
> > have received almost no feedback  on Ebay :( I hope that is a good  sign.
> >
> > Bye,
> >  Said
> >
> >
> >
> >  _______________________________________________
> > 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.
> >
>
> --
>
> 73,
> Mike, N1JEZ
> "A closed  mouth gathers no feet"
>
>
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