On Thu, 15 Nov 2012 06:07:28 -0800, Jim Lux <[email protected]> wrote:
>On 11/15/12 5:33 AM, David wrote: >> On Thu, 15 Nov 2012 05:02:54 -0800, Jim Lux <[email protected]> >> wrote: >> >>> On 11/15/12 4:30 AM, David J Taylor wrote: >>>> i just used this to with a raspberry pi with good success. >>>> >>>> https://www.adafruit.com/products/746 >>>> >>>> james >>>> =============================================== >>>> >>>> It looks idea, James, but ... with the 15 mm square patch antenna it >>>> seems deaf compared to similar devices with 25 mm antennas. Perhaps >>>> understandable, but I just bought one and it's been sitting for well >>>> over an hour and not yet acquired lock. The device I bought from China, >>>> sitting next to it, has been happily locked for that whole period. (As >>>> I'm running a test I don't want to unlock the other device). Just a >>>> caveat for someone considering using these devices indoors - size matters! >>>> >>>> 25 mm antenna device: >>>> http://www.satsignal.eu/ntp/NEO-6M-under-initial-test.jpg >>>> http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html >>>> >>>> Cheers, >>>> David >>> >>> >>> ALl good ideas.. but I was looking more for something a bit more >>> packaged.. like a hockey puck with wires coming out. >> >> I picked up a used Garmin GPS18-5Hz hockey puck to play with and after >> updating the firmware, have gotten good results with the cable going >> out a window and the unit sitting on the lower edge of the roof. Its >> 5 pulse per second output has 60ns of resolution according to the >> Racal Dana 1992 I repaired implying about a 16.6 MHz timing clock. >> > >That's the kind of thing I'm looking for.. or the Synergy TrakPuck ... >or one of those pods that came with mapping software 5-10 years ago. >I wonder if there's a new version of the GPS18, since I need something >that is available off the shelf (and likely to remain so for at least >2-3 years).. > >Is there a timing output on the GPS16x? (or are the serial messages >synchronized in some way) So the 16x manual says. As far as I know, all of the Garmin LVC, HVC, and 5Hz versions of their receivers have a timing pulse output. The GPS18 series that I have was replaced by the GPS18x series. Some of their receivers have "TIA-232-F (RS-232) Compatible Polarity" which means exactly that. They do not provide RS-232 voltage levels so for my GPS18-5Hz, I had to hack together a little non-inverting level shifter (two transistors, some resistors, and a dual power supply) to convert the 0 to 5 volts into -12 and +12 volts. _______________________________________________ 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.
