On 4/15/13 10:40 PM, bg wrote:
Chris,Chokering is not needed. Measured quality antennas are listed at http://www.ngs.noaa.gov/ANTCAL/ Or at http://www.geopp.de/index.php?sprachauswahl=en&bereich=0&kategorie=34&artikel=62 /Björn
A lot of the antennas on that list are choke ring type. If you are doing geodetic work, millimeter scale changes in phase center are important. For time transfer, maybe not.. 1mm is 3 ps, after all.
A ratty old patch antenna has a phase center variation of a few cm at most, and that's 30-50 ps.
the effect of a strong multipath (which is what the choke ring suppresses) would be a LOT bigger than that..
_______________________________________________ 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.
