Does anyone else see a GNSS +1 sec. Clock Error on their 8600 when GNSS is Locked?

Dick / KC9YRA

I recently received my 8600. No problems during setup.

After a cold startup of the 8600 and then starting SSDR the 8600 Settings, Radio Setup, RX panel shows TXCO Locked and the SSDR clock display matches the computer system time (updated by Dimmension 4) and matches WWV. This seems normal.

When the GNSS locks the SSDR clock displays jumps +1 sec. compared to WWV and computer system time.

SDR 3.8.23
Settings, Radio Setup, GPS Panel shows
GNSS installed
Sat Tracked 15
Sat Visible 30
UTC Time is +1 sec.

Settings, Radio Setup, RX Panel shows GNSS Locked
This happens on Win 11 pro and Win 10 pro computer systems.

Have not seen this posted before

Jim KJ3P

After a few minutes of warmup and GNSS locked, my 8600 also settles at about +1 second ahead of WWV. 12 tracked/25 visible. I'll check it again in a couple of hours.

k3Tim

Interesting finding. Observed same behavior on a 8600. Perhaps something to do with leap seconds:

https://www.nist.gov/pml/time-and-frequency-division/time-realization/leap-seconds

k3Tim / 7

Mike-VA3MW

Here is your answer. They differ by the number of Leap seconds since Jan 1980.

https://www.nist.gov/pml/time-and-frequency-division/how-utcnist-related-coordinated-universal-time-utc-international

k3Tim

Thanks for the reply Mike.

With the 8600 setup as an NTP server, the local PC shows exactly the correct time w/o the leap second offset.

Mike-VA3MW

it was suggested to me that if you are seeing a 1 second difference to please open a support ticket.

Bob Cheek

It has been said that a man with more than one watch has no idea what time it actually is. I'm there!

I have two external time sources. A Tracomex WWV time source and a Spectracom Netclock/GPS time source. These two time sources agree perfectly.

The GNSS time displayed on the Flex 8400 (SmartSDR 3.9.18) is consistently 1 second ahead of the two time sources. I also re-synced the computer system clock and it now agrees with the two time sources.

The GPS on the Flex shows 14 / 15 satellites tracked but it doesn't tell me which GPS constellation I am synced to. That might be a good piece of information to have.

Is this a know issue or does it need to be posted on the Alpha Test site?

Regards,

Bob - N4RFC

Mike-VA3MW

Please open a support ticket so that this gets tracked correctly.