[time-nuts] New (refurbished) LPRO-101 GPSDO

[Bob Camp]

Hi

Straight out of the box, an LPRO should be within <2x10^-10 after an hour on power. That's with no disciplining and just normal luck in terms of it getting banged about in shipment. That also assumes it was set properly before it was shipped.

As long as your antenna is outdoors with a good view of the sky to the south, the receiver should find enough sats to stay in timing mode all the time. In the horizontal plane the sky within +/- 30 degrees of due north is not very important for GPS. Vertically a view to within 20 degrees of the horizon is considered ok for this sort of thing. 

I'd give it a bit more time, but it sounds flaky to me.

Bob


On Oct 17, 2010, at 5:55 AM, David McClain wrote:

> I just received my LPRO-101 with a GPSDO control on it, from TenMhz.com. After fiddling with getting a good placement for the GPS antenna, so that it doesn't keep losing the satellites, I have been attempting to discipline the oscillator for more than 24 hours.
> 
> At this point, the LED has been toggling red / green for the past 24 hours which indicates solid GPS acquisition and < 5e-8. But it isn't locked to NIST until it turns solid green which indicates < 5e-11.
> 
> Since this is a first deployment at my location, is it reasonable behavior for it to take longer than 24 hours to lock to NIST through GPS? Or do you think something may be wrong with the device.
> 
> I already know by comparison to WWV that I'm within a few mHz of being aligned, but noise in the measurements, human impatience, and wander in the soundcard clock, prevents me knowing any better than this. So already I'm < 5e-10. But that's about all I know until I see it lock. (If it ever does...)
> 
> eh?
> 
> Dr. David McClain
> Chief Technical Officer
> Refined Audiometrics Laboratory
> 4391 N. Camino Ferreo
> Tucson, AZ  85750
> 
> email: dbm at refined-audiometrics.com
> phone: 1.520.390.3995
> web: http://refined-audiometrics.com
> 
> 
> 
> On Oct 15, 2010, at 16:00, Magnus Danielson wrote:
> 
>> On 10/16/2010 12:08 AM, Bob Camp wrote:
>>> Hi
>>> 
>>> It's a crazy world when it comes to self signed certs.
>>> 
>>> You have at least 5 OS's you need to consider (MS, Linux/FBSD, OS-X, I-OS, Android). You need to think about both browsers and mail clients. Each of those come from a half dozen sources on each platform. Then you have configuration options on each. That's a lot of combinations.
>>> 
>>> Each combo seems to have a different idea of what not to do when they see a self signed cert. If you want to be able to handle all of them, even "real" certs may have issues. There are indeed several common combo's that are a major pain with a self signed cert.
>>> 
>>> No, I didn't write any of the code with the problems in it. I also don't want to get into the details of what and where. This really isn't the forum for that sort of thing. I'm not out to bash any particular solution, only to point out that there are indeed issues.
>> 
>> Do handle part of the mess, we have setup our local root cert at the computer club, and then sign our server certs to that. I did a major overhaul on the infrastructure for that. It is still not "real" safety routines, but ah well. We provide a cert download which quickly solves the cert issue with most browser.
>> 
>> Seems to work for our myriad of server and client OSes and clients.
>> 
>> There is various ways to get "real" root certs, but depending on degree of uhm... safety... it may be argued of their capabilities. There is efforts to build a chain of trust for a stable free root cert, but it is so far nog included in any major browsers.
>> 
>> Essentially it's a mess. I'm only scratched the surface here.
>> 
>> Cheers,
>> Magnus
>> 
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