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

[mike cook]

Le 17/10/2010 11:55, David McClain a écrit :
>
> 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 don't have this box or an LPRO, but if the manafacturer says 24hrs is 
OK, then I guess that should be enough.  You may need to give them a 
call. However am wondering if you are getting reflected path GPS 
signals. You said  that you had to fiddle with the antenna placement. 
Are you in an urban jungle? I have a situation where I can see 
satellites at all times, but once or twice a day I am getting strong 
reflected signal which is disturbing the GPS 1PPS. It is due to buidings 
opposite my north facing office where the antenna sits. The issue is 
seen with my TBOLT, Z3801A and  independent Oncore GPS engines all of 
which are not the latest hardware.  That would cause the PLL to be 
constantly chasing a moving target.
> 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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