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

[nlsa at nlsa.com]

Dear friends,

Another small hiccup in the Heols Design receiver: the list of GPS satellites is always empty.  Heols knows about it.

Michael

 

From: Steven Sommars <stevesommarsntp at gmail.com> 
Sent: Wednesday, March 29, 2023 8:15 PM
To: Discussion of precise time and frequency measurement <time-nuts at lists.febo.com>
Cc: nlsa at nlsa.com; Fleeson, Richard <RFLEESON at c-span.org>
Subject: Re: [time-nuts] Re: NTP server replacement GPS receiver

 

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.