[time-nuts] Re: NTP server replacement GPS receiver

[Steven Sommars]

Heol Design has been responsive to my support questions, even though I am
not a customer (just an observer).

I've seen two issues:  #1  Off by 1 second for a one second duration every
hour, beginning XX:59:01     I'm told this is due to software version
mismatch.
I'm aware of only one public NTP server with this problem; that site is
unable to make the needed software change.
#2   Off by one second for a duration of one hour at the beginning of
specific GPS weeks.  I observed this  2023-03-12 00:00 and reported to Heol.
Heol Design told me that the problem comes from the way Tymserve-Datum
attempted to avoid GPS WNRO (using leap seconds) and that the problem is
expected to recur every 70 or 71 weeks.
I was able to verify this from my historical NTP logs.   They're working on
a fix.

Versions do matter.  Check with Heol Design for the required software
versions and updates.