All -
I have made substantial progress on my HP 58503A, but I am not
quite there yet. By watching the internal lights and the data on the
processor bus I could see that the CPU was starting to boot and then
restarting every ~15 seconds. Furthermore, the reset circuit didn't
seem
to be working right. Sometimes when I power cycled it the front panel
lights would flash to indicate a self-test, other times they would not.
This seemed to indicate that the system was not being reset
correctly on
start-up. More telling, when I manually triggered the reset generator
chip, the system would not ever flash its front panel lights even
though
I could see that the CPU was being reset per the internal lights.
The problem, as it turned out, was more mechanical than
electrical.
As shown in the attached photo, someone had put the case back together
with a screw that was too long! It dug into the board and cut two
traces, one of which was the reset line for the UART chip (and probably
some other chips as well - I didn't fully trace the line). Once I
repaired these two traces (red wires in my picture) it booted right up
and even passed its self-test!
However, the story does not end there. I now have it booting and
appearing to "work" but I can't get it to track satellites. I manually
set the location, date, and time with the following commands:
GPS:INIT:DATE (date)
GPS:INIT:POS (position)
GPS:INIT:TIME (time)
I then setup the unit (inside, but with the GPS antenna near a
window) and left it turned on overnight. However, no dice. The system
does not display errors but won't track any satellites. Here is the
results of a SYSTEM:STATUS? command:
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: 14 _______ Time
____________________________
PRN El Az PRN El Az UTC 05:08:22 [?] 11
Oct 2018
* 1 -- --- *10 -- --- GPS 1PPS Invalid: not
tracking
* 2 -- --- 16 35 50 ANT DLY 0 ns
* 3 -- --- *23 55 129 Position
________________________
* 5 -- --- 26 10 41 MODE Survey: 0%
complete
* 6 -- --- 27 21 96 Suspended: track <4 sats
7 57 267 30 25 257 INIT LAT N 47:42:01.770
* 8 13 127 INIT LON W
122:16:26.770
9 81 141 INIT HGT
+20.00
m (MSL)
ELEV MASK 10 deg *attempting to track
HEALTH MONITOR
.........................................................
[ OK ]
Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS
Rcv: OK
scpi >
Is there anything else I can try?
Thanks in advance,
Matthew D'Asaro
On 10/07/2018 12:26 AM, Mark Sims wrote:
The 58503A needs a null-modem pinout serial cable to connect to a
PC. The baud rate defaults to 9600:8:N:1
_______________________________________________
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.
_______________________________________________
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.
