>From a geodetic antenna manufacturer, I got the recomendation to keep 1m >separation between antennas. This was for a sub 5cm position application.
But no white papers to quote... /Björn <div>-------- Originalmeddelande --------</div><div>Från: Dave M <[email protected]> </div><div>Datum:2014-10-08 17:40 (GMT+01:00) </div><div>Till: Discussion of precise time and frequency measurement <[email protected]> </div><div>Rubrik: Re: [time-nuts] WTB: GPS Antenna Splitter </div><div> </div>Bob, Thanks for that. My intent was to mount the antennas on yardarms on a mast. Both antennas will be at the same elevation, just separated horizontally by a couple feet (not 10ft). My concern (and I think you answered it) was how far apart could I place the antennas without having to do another survey when I switch them around. As an alternative, I could enter the antenna coordinated manually into each GPS when I switch antennas. That should avoid a new survey each time. Then, the distance between the antennas shouldn't matter. Thanks for the info!! Dave M Bob Camp wrote: > Hi > > Missed the survey question… > > If a ns in free air is about 1 foot (30 cm), then you probably want a > survey that is better than 6” to keep the error down. You do not want > to have the antennas on top of each other, so yes, the GPS will need > a survey / location each time you change antennas. If you go with the > 10’ spacing, then you will get some pretty big jumps without > switching the location. > > Bob > > On Oct 6, 2014, at 4:01 PM, Dave M <[email protected]> wrote: > >> Does anyone in the group have, or can point me to, a low-cost (but >> not cheap) 2-port splitter for a GPS antenna? Those on Ebay are >> rather expensive. >> >> I have two GPSDO units, and have both an older timing antenna and a >> new choke ring antenna (Thanks, Pete L). I already have one 2-port >> splitter (working well), but my intent is to connect both antennas >> through the splitters and a couple coaxial relays so that I can, >> with the twist of a switch, allow me to run each GPS from a >> different antenna, or both from the same antenna. I would like to >> gather some data as to the differences between the two antennas. I >> know I could switch the connections manually, but I like the idea of >> a switch to sort of automate the connections, and I'd need another >> splitter anyway. >> >> Before I go to the trouble and expense of building upon this idea, >> are there any comments as to the value of the project? >> Some questions come to mind: >> I'm thinking about mounting both antennas on the same mast, at the >> same elevation, just separated by a couple feet. Any problems that >> I should be aware of by putting both antennas so close together? >> Will that small distance have a noticeable effect when switching a >> receiver from one antenna to the other? Will the GPS notice the >> difference and want to do another survey? >> >> Thanks for your comments. >> Dave M >> _______________________________________________ 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.
