On 18 December 2016 at 14:31, Tim Shoppa <tsho...@gmail.com> wrote: > A common misconception, is that holdover is the opposite of GPS lock. > Sometimes we might even talk about the two as if we're in one or the other. > But really the power-on state, is that we're in neither holdover or GPS > lock. > > Holdover means the smartclock previously had GPS lock and had used it to > characterize the aging of the OCXO, and is maintaining the EFC > extrapolation, such that it believes it can still produce accurate time and > frequency through the GPS loss. > > The state of your clock at the moment, is that it has never had GPS lock > since regaining power, it does not know what time it is, and it has not > characterized or extrapolated the aging of the OCXO. So it is definitely > not in holdover. > > Tim N3QE >
Cheers Tim, that makes sense. I'm a bit concerned it has not managed to track a single satellite, despite it has been on 5 hours or so. But perhaps things have improved, as its not attempting to track 6 (PRN=15, 2, 21, 25, 26 and 28), whereas before it was attempting to track just with a PRN of 32. I'm hoping its current status (see below), is looking more hopeful than what it was before. scpi > scpi > SYSTEM:STATUS? ------------------------------- Receiver Status ------------------------------- SYNCHRONIZATION ........................................... [ Outputs Invalid ] SmartClock Mode ___________________________ Reference Outputs _______________ Locked TFOM 9 FFOM 3 Recovery 1PPS TI -- Holdover HOLD THR 1.000 us >> Power-up: GPS acquisition Holdover Uncertainty ____________ Predict -- ACQUISITION .............................................. [ GPS 1PPS Invalid ] Tracking: 0 ____ Not Tracking: 6 ________ Time _____ +1 leap second pending PRN El Az UTC 14:43:22 [?] 01 Jan 1998 *15 -- --- GPS 1PPS Invalid: not tracking *20 -- --- ANT DLY 0 ns *21 -- --- Position ________________________ *25 -- --- MODE Survey: 0% complete *26 -- --- Suspended: track <4 sats *28 -- --- INIT LAT N 51:39:03.825 INIT LON E 0:46:36.278 ELEV MASK 10 deg *attempting to track INIT HGT -14.04 m (MSL) HEALTH MONITOR ......................................................... [ OK ] Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK scpi > SYSTEM:STATUS? ------------------------------- Receiver Status ------------------------------- SYNCHRONIZATION ........................................... [ Outputs Invalid ] SmartClock Mode ___________________________ Reference Outputs _______________ Locked TFOM 9 FFOM 3 Recovery 1PPS TI -- Holdover HOLD THR 1.000 us >> Power-up: GPS acquisition Holdover Uncertainty ____________ Predict -- ACQUISITION .............................................. [ GPS 1PPS Invalid ] Tracking: 0 ____ Not Tracking: 6 ________ Time _____ +1 leap second pending PRN El Az UTC 16:59:08 [?] 01 Jan 1998 * 8 -- --- GPS 1PPS Invalid: not tracking *10 -- --- ANT DLY 0 ns *11 -- --- Position ________________________ *12 -- --- MODE Survey: 0% complete *13 -- --- Suspended: track <4 sats *30 -- --- INIT LAT N 51:39:03.825 INIT LON E 0:46:36.278 ELEV MASK 10 deg *attempting to track INIT HGT -14.04 m (MSL) HEALTH MONITOR ......................................................... [ OK ] Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK _______________________________________________ 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.