Martyn,
In working with a 6T receiver we have noticed that sometimes the
reported offset correction is not correct. These instances appear to be
infrequent, and have only been noted as a single instance at a time. For
example you will occasionally get a -10.2nS correction when you should
get a positive one, or vice versa. Simply changing the sign of the
offending correction value appears to make it correct.
This doesn't sound exactly like what you are seeing, however.
Hope the info helps!
Dan
On 2/4/2015 12:00 PM, [email protected] wrote:
Hello,
I am using a LEA-6T GPS chip with the DS1123LE-50 delay line to correct the
jitter of the 1 pps output from the GPS chip.
The correction works very well, dropping the peak to peak jitter of the 1pps
output from about 20 ns to < 3 ns.
However, I randomly get a big jump of the 1 pps pulse, by many
millisceconds.
After lots of research, checking code and hardware, it seems the DS1123LE-50
chip randomly produces it's own long pulse.
I have monitored the pulse going into and out of the delay line
The input pulse remains constant (I can't remember exactly the pulse width,
I think 10 us).
But suddenly a large output pulse of many milliseconds appear.
Some chips don't seem to have this problem. Other chips can go wrong, 20
times in an hour, then run perfectly for a day or so.
I am blaming my software guy, he is blaming the chip.
Has anyone else used this delay line and seen anything similar?
This chip is now apparently obsolete, but I don't want to change yet as I
have a few years worth of stock of these chips.
Regards
Martyn
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
