Author: Rudi Stoeger Ladies and Gentlemen Just I got the information: Since 2011-02-15 15:00 UT the JAVAD TRE_G3TH DELTA in the WTZZ GPS+GLONASS Permanent Tracking Station here in the Geodetical Observatory Wettzell, Germany, use the H-Maser EFOS 18 for external input reference. With best regards Rudi