[time-nuts] 58503A alarm light on, but :SYSTEM:STATUS? indicates all is ok
Dr. David Kirkby (Kirkby Microwave Ltd)
drkirkby at kirkbymicrowave.co.uk
Sat Apr 4 11:49:20 EDT 2015
On 1 Apr 2015 23:24, "Bob Camp" <kb8tq at n1k.org> wrote:
> Best guess is that your antenna is not doing the job.
That's possible. It was supposed to be an Andrews antenna, but there's
nothing on it to indicate that to me. But it is well sited. I expect
antenna issues can explain the log entry
092:20150330.19:30:37: Holdover started, not tracking GPS
> If the HP is in lock long enough to predict a good holdover (there are
multiple limits) you can have
> holdover with no alarm.
Which is what I did have with the above log entry.
Log 103:20150331.00:00:00: Power on
Log 104:20150331.00:08:19: GPS reference valid at 20150331.15:02:08
Log 105:20150331.15:03:16: GPS lock started
Log 106:20150331.17:01:37: Position hold mode started
> If it goes into holdover and is not “ok” by the various limits, you will
> alarm + holdover.
But I have never seen that.
> After being in holdover for a while (how long depends) you will get an
> values are in the 24 hour range if it’s been on for a while.
But that never happened.
I got an email from someone else, who also has an 58503A, and says his
recently showed "Alarm", with nothing in the log. He postulated whether it
could be to do with the upcoming leap second, although I would have thought
that on such an old design, if such issues existed, they would have been
discovered before now.
I just checked the receiver a minute or two ago, and the Alarm LED was on,
as it has been for a few days now. I then sent
scpi > :SYSTEM:STATUS?
over the RS-232 and the LED went out. I want not expecting this, so can't
say whether the *CLS or the :SYSTEM:STATUS? caused it to go out. (I would
guess the first, but I don't know).
I note the display now shows the pending leapsecond, which it did *not*
when I posted this on April the 1st.
When would the clock be expected to know about the leapsecond? Somewhere
8:59:42 on 1st April 2015 and 16:32:49 on the 4th April 2015, the receiver
seems to have learned about the leapsecond, which will be added at the end
See below, for what it shows now. The 9.2 us/initial 24 hrs is a lot worst
than it was a few days ago (4.9 us/initial 24 hrs), but 4.9 was unusually
low. I have never seen it that low before, but I don't keep watching this
thing all the time. I bought it mainly for a lab reference.
scpi > :SYSTEM:STATUS?
------------------------------- Receiver Status
SYNCHRONIZATION ............................................. [ Outputs
SmartClock Mode ___________________________ Reference Outputs
>> Locked to GPS TFOM 3
Recovery 1PPS TI -11.8 ns relative to
Holdover HOLD THR 1.000 us
Power-up Holdover Uncertainty
Predict 9.2 us/initial 24 hrs
ACQUISITION ................................................ [ GPS 1PPS
Tracking: 6 ____ Not Tracking: 1 ________ Time _____ +1 leap second
PRN El Az SS PRN El Az UTC 15:32:49 04 Apr
12 70 233 88 22 14 276 GPS 1PPS Synchronized to UTC
14 29 310 39 ANT DLY 0 ns
15 20 171 39 Position
17 23 43 49 MODE Hold
24 76 108 71
25 30 239 33 LAT N 51:39:04.143
LON E 0:46:36.402
ELEV MASK 10 deg HGT +47.15 m
HEALTH MONITOR ......................................................... [
Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv:
scpi > :DIAG:LOG:READ:ALL?
Log status: 106 entries
<same as posted before - there are no new entries>
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