Hi Depending on your local antenna restrictions, you may or may not be able to put up a proper outdoor antenna. If you can, it's well worth it. They are available for < $40 on the e-place. The normal ones mount on the end of a piece of iron pipe, so setting up a mound is normally pretty easy. I just use a flange and screw it into an available chunk of wood on the outside of the house. The mounts I use are rarely more than 18" tall, a little Krylon on the pipe pretty much makes it disappear. Total cost (assuming you don't fall off a ladder) - under $50.
Bob On Oct 17, 2010, at 12:32 PM, David McClain wrote: > Hi Bob, > > Well,... sort of... I live in a rather cramped housing development, where the > neighbors wall is about 20 feet from my window, and his wall is about 12 feet > high. So that seems rather marginal for a southern view from the windowpane > of my lab. > > As it happens, I moved the antenna about 4 feet lower, to a slightly more > restricted view of the sky, and the LPRO pretty quickly locked to its best > state. Then after fiddling some more with the antenna it must have lost the > birds, but still remained in its second-best state. Now after more fiddling, > the sats were reacquired and the LPRO is back to its best locked state. What > a huge difference this makes. > > Incidentally, the antenna was originally located about 1 foot from a Comcast > coax line running around the house, just below the eaves. I have had no end > of frustration with Comcast equipment, and so I wonder if that was the > culprit. Right now the antenna is sitting slightly higher for a better view > of the south, but careful to keep at least 3-4 feet from the Comcast coax > line. Everything is working great at the moment. > > Very happy camper. Thanks so much for all your input. I'll give the > groundplane idea a try with one of my wife's cookie sheets... > > Cheers, > > Dr. David McClain > Chief Technical Officer > Refined Audiometrics Laboratory > 4391 N. Camino Ferreo > Tucson, AZ 85750 > > email: [email protected] > phone: 1.520.390.3995 > web: http://refined-audiometrics.com > > > > On Oct 17, 2010, at 08:09, Bob Camp wrote: > >> Hi >> >> The antenna should do fine just sitting on the roof. It will do better >> sitting over a ground plane. >> >> Does the antenna have a clear view of the sky to the south? >> >> Bob >> >> >> On Oct 17, 2010, at 10:15 AM, David McClain wrote: >> >>> Well, not exactly an urban jungle here, but there could be multipath off >>> the neighbor's home... Thanks for that suggestion. I will try moving the >>> antenna about. >>> >>> When I first deployed it, the GPS would go solid reception for a while, and >>> it actually claimed to lock, after only an hour or so. But it kept losing >>> the birds and would go back into hunt mode after about 20 minutes of lock >>> time. I wasn't sure that I could trust the lock indication after so short a >>> time. And I didn't like the sporadic lock conditions. >>> >>> So I tried duct taping the antenna to the roof tiles that I could reach and >>> got solid GPS reception, but no lock. >>> >>> The antenna is a little black hockey puck with a magnetic base. I wonder if >>> it would do better affixed to a metal ground plane? >>> >>> First time user of a GPSDO and so I don't know what to expect. But I'm also >>> beginning to understand better that a GSPDO probably is more than was >>> warranted for the needs of a solid reference oscillator for radios. Now >>> that I'm learning more about Rb and GPSDO's in general, I probably could >>> have got by quite well with just a bare LPRO. And I am also beginning to >>> understand that GPSDO's don't necessarily have internal Rb references -- >>> looks like the T'Bird is just a really good OCXO with a GPS discipline. And >>> everyone is raving about T'Birds... The LPRO has an internal Rb reference >>> and an untamed VCXO. >>> >>> Thanks for all the advice! >>> >>> Dr. David McClain >>> Chief Technical Officer >>> Refined Audiometrics Laboratory >>> 4391 N. Camino Ferreo >>> Tucson, AZ 85750 >>> >>> email: [email protected] >>> phone: 1.520.390.3995 >>> web: http://refined-audiometrics.com >>> >>> >>> >>> On Oct 17, 2010, at 06:07, mike cook wrote: >>> >>>> >>>> >>>> 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: [email protected] >>>>> 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 >>>>>> >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- [email protected] >>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>>> >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
