Anyone using Flex GPSDO as time server? As a waveform?

  • 27
  • Question
  • Updated 1 year ago
The GPSDO option in my 6500 is a full function GPS receiver, delivering latitude, longitude, altitude, speed, and 10 MHz reference frequency.  But it also derives UTC time, presumably accurate to the microsecond.

SSDR only makes use of the freq. reference, but it will display all the other parameters once per second. Actually, the Maestro seems to synchronize itself to the GPSDO time.

It would add value to my station (and computer network) if the GPSDO could function as an NTPD network time server on the Ethernet.  (For NTPD, millisecond accuracy may be enough.) The software to do this is standard, but the most accurate time information is buried in the radio away from our reach as non-SSDR-developers.

My questions are
  • has anyone found ways to get accurate time (microseconds, ideally) through the API?  and 
  • does anyone have an idea how to create an NTPD module that would work beside SSDR?  Presumably it should come from a "time-nut" rather than from Flex developers.

I have looked at the Waveform interface a little to see if it could possibly work for NTPD.  It might be a stretch, but maybe someone can speak to that.  I don't see any recent Waveform development.  Maybe that's telling us something?

Thanks for your thoughts!

73 Martin AA6E
Photo of Martin Ewing AA6E

Martin Ewing AA6E

  • 348 Posts
  • 85 Reply Likes

Posted 2 years ago

  • 27
Photo of Ria - N2RJ

Ria - N2RJ, Elmer

  • 2334 Posts
  • 973 Reply Likes
I would also love this but... I think they said they weren’t interested in doing that. That said you can get a cheap GPS time source.
Photo of John - WA7UAR

John - WA7UAR

  • 211 Posts
  • 47 Reply Likes
If folks are interested in this option then please click the "me too" link at the top of this thread.
Photo of John - AI4FR

John - AI4FR

  • 327 Posts
  • 98 Reply Likes
I’d like to see this option as well. It might even help with sales of the GPSDO.
An observation I have noticed: If I set my PC clock using the net, it is nearly spot on accurate when compared with WWV using a non-SDR. When I compare the PC time with GPSDO time, the GPSDO time is about .3 to .4 seconds behind the actual time. When I compare the GPSDO time with WWV while using the Flex 6700 all is well. So I guess the time it takes to receive the signal and convert it is the lag I am seeing so I have been using the net to set the clock in my PC.
Photo of KY6LA - Howard

KY6LA - Howard, Elmer

  • 3832 Posts
  • 1674 Reply Likes

The thing that sold me on the GPSDO was the "proposed" ability to use the time signal to synch packets for diversity reception between a couple of different as to be able to take advantage of diverse antenna sites.

I suppose its on the to do list... but nothing heard for several years now

Photo of Andrew Russell

Andrew Russell

  • 287 Posts
  • 46 Reply Likes
That is what I want too. Maybe with 3.0 and multiple clients we can share receiver resources with each other for long baseline diversity.
I have a mate 20 km east of me with a 6000 but no GPS (yet).
Andrew VK5CV
Photo of Martin Ewing AA6E

Martin Ewing AA6E

  • 348 Posts
  • 85 Reply Likes
I wouldn't expect Flex to devote serious manpower to timekeeping, but community-supplied add-ons were supposed to be part of the Big Vision for the 6000 series, at least originally.
Photo of Bill -VA3WTB

Bill -VA3WTB

  • 4656 Posts
  • 1099 Reply Likes

 Tim - W4TME, Customer Experience Manager

  • 8935 Posts
  •  3376 Reply Likes

Official Response

The short answer is no.  The radio is not an NTP/SNTP server.

The long answer is it is possible, but it isn't anything we are planning to look into anytime soon.
Photo of Pat - WH6HI

Pat - WH6HI

  • 644 Posts
  • 115 Reply Likes
I had made the suggestion several years ago when i bought my 6500 with the GPSDO.  In the time since then, I bought a TimeMachines TM1000A and it serves as my NTP server for all my computers in my house.  It shares the GPS antenna with my 6500.  Having worked in a calibration lab many years ago makes me rather anal about time and frequency accuracy.  But I think Flex is missing the mark in not providing simple time server capabilities since everything is there to do the code. 
Photo of kr4k


  • 75 Posts
  • 17 Reply Likes
Wish Flex would turn on the highest accuracy time tagging of the IQ samples. TO me that is much more important than an NTP server. Second would be to use this time tagging to sync samples on multiple slices.
Photo of Watts - K4QJZ

Watts - K4QJZ

  • 82 Posts
  • 17 Reply Likes
It would open a few doors, one customer of mine went with RFSpace because it did not have it. But then in fairness the consumer world has other higher priorities.
Photo of Mark Erbaugh

Mark Erbaugh

  • 530 Posts
  • 48 Reply Likes
A time server would be nice, but not critical for me. My critical need for time is for FT8 eat al, time synchronization and internet time servers with Windows clients (Dimension 4) are fine for that.

What I do want to see is time stamping of the. VITA-49 data packets so we can do diversity with multiple receivers.
Photo of Steve - N4TTY

Steve - N4TTY

  • 103 Posts
  • 11 Reply Likes
I bought a GPSDO several years ago, and I'm really wondering why.  I think I just wasted my money!  Now if I was able to get access to that GPS clock it would be money well spent.  Flex is using it to display accurate UTC time on the SDR software screen, how hard would it be to make that available at least through an API?

I use Meinberg at the moment for my PC, but it sure seems like a waste when the info is just inches away!  I may look into the Time Machines TM1000A as mentioned earlier in this thread.  That looks as if it would have been a much better way than to have spent the bucks for the GPSDO.

Flex, while you don't seem to want to do this, I think you are missing a marketing opportunity to sell more GPSDO's (as was also mentioned earlier in this thread)!
Photo of Pat - WH6HI

Pat - WH6HI

  • 644 Posts
  • 115 Reply Likes
Here is an idea for those that are code savy with the Rasebery computer. Interface the 10 MHz GPSDO reference and creat an NTP server with it.
Photo of Ted  VE3TRQ


  • 641 Posts
  • 226 Reply Likes
oI rather doubt the internal GPSDO has the appropriate output readily available, but if you have an external GPSDO supplying the 10MHz signal, that unit likely also has an RS232 interface which can be fed into software on a computer of your choice to synchronize your clocks. The software to do that is open source / freely available.