I recently acquired a pair of Meinberg M600's (with GPS-CON downconverters).
>From the usual auction site got a dual band antenna (for futureproofing), a 2nd hand mini-circuits ZN4PD1-63W-S+, several SMA BIAS-TEE to prevent DC issues, and an assortment of coax cables to connect everything up. To power the antenna I used a ublox M8Q series without a BIAS-TEE connected to the splitter, and then tested with another ublox (a NEO 7M) via a BIAS-TEE that it could also see satellites and that both could get a 3D fix. When I connected up each of the M600's, they eventually acquired positions and acheived sync, but while the ublox receivers rarely do not show a 3d fix, both of the M600's will show the a similar number of satellites in view as the ublox, and sometimes more than one "Good" satellite, but the "Selected Satellite Set:" never seems to change from "00 00 00 00". I presume that as its a timing device, that once it has surveyed its position, it only needs one satellite to solve for time, and the MRS status shows "Signal available, Is master, Is locked, Is accurate" with an offset that is usually within -50 to -120ns but I'm lost as to what the "Selected Satellite Set:" should be displaying. At the moment, one of the Meinbergs shows 10 in view and one good, and one of the ublox shows 12 in view and 8 used. I tried with one of the Meinberg's (via the GPS-CON) connected directly to the antenna with no improvement, and tried with a patch antenna directly connected, again with no improvement, and different ports on the splitter etc. The antenna location is by no means ideal (west facing window in fairly central London), but none of the ublox receivers (just basic Max8 and Neo7m, no timing ones yet) have had any trouble getting and keeping a 3D fix. >From my "naive" viewpoint, it looks as if the Meinbergs are a little "deaf", but I'm guessing that I'm missing something. Any suggestions gratefully received. Cheers Arne _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.