Jim, Are you trying to find out how to hook up a receiver in your office/radio room to an antenna that is some ways away? Or are you specifically trying to remotely hook up a receiver near your antenna? If the former, just use RG-6, like for cable TV, with adapters on each end. RG-6 has such low loss that the impedance change is not an issue. I've got a 30+ ft run up to the attic to a cheap GPS puck antenna for my setup. Others have much longer runs and it works OK.
Bob ________________________________ From: jim s <jwsm...@jwsss.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Tuesday, July 1, 2014 4:56 PM Subject: Re: [time-nuts] FASTRAX GPS I went back thru this thread to look for the answer, and did not see it so am asking. The one of these I have has a threaded female connector on it. One of the ones in Tom's page has a smooth sided connector, FWIW. I wonder if this would work with one of the 5m SMA male active antenna units will work with it? http://www.ebay.com/itm/321295751672 This one happens to be 5 meters long and is active. I am guessing because the unit has antenna power this is the sort of item to use? I want a long run because where I plan to use it is some distance from clear line of site. thanks Jim On 6/20/2014 8:31 AM, Tom Van Baak wrote: > Hi Ernie, Jason, (also Hal, Chris), > > I'm able to get NMEA and 1PPS out of the Fastrax/iTrax130 board now. > > Before I sink any more time into this project, have any of you made 1PPS > measurements? > > Compared to ublox, using the same antenna, these units take tens of minutes > or even hours to lock. And they have a bad habit of being close to UTC for a > few hours but then gradually wandering off by tens or hundreds of > microseconds. > > A power cycle puts them back on track (aligned with UTC), so it would seem to > be a firmware issue rather than antenna or reception. A similar thing happens > on three different boards I have evaluated over the past two weeks. > > Now, when they are working right, the 1PPS has an RMS deviation of around 20 > ns, which I've come to expect as typical for cheap GPS/1PPS receivers these > days. But the long lock times and unexplained 1PPS drift make them unreliable > for GPSDO or serious timing work, even at $12 each. > > It might be me, so I'm asking if you've seen anything similar. The binary > command set looks tempting, but I usually don't play with that until the unit > can be trusted to give reliable NMEA and 1PPS output. > > Unfinished page: http://leapsecond.com/pages/itrax/ > > /tvb > > ----- Original Message ----- > From: "Ernie Peres" <erniepe...@aol.com> > To: <time-nuts@febo.com> > Sent: Wednesday, June 11, 2014 4:11 AM > Subject: Re: [time-nuts] FASTRAX GPS > > >> Hi Jason, >> >> >> I figured out a different pin assignments.... >> >> hold the PCB so that the SMA antenna connector is looking to right and under >> the PCB. >> >> open- 1 2- Ant power presently connected to pin nbr 4 >> TX- 3 4- Main power +3 volt >> RX- 5 6- 1PPS >> open- 7 8- Grnd power -3 Volt >> >> the unit takes about 60mA @ 3,0 volt and comes-up in NMEA mode.. 9600 Baud. >> I use the FASTRAX_WORKBENCH_522 software. >> I wonder if anybody has other pin arrangement/connection. The 2 open pins is >> UNK and also not sure if pin nbr 4 is the main power or perhaps the pin nbr >> 2......?? >> >> Rgds Ernie. >> > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.