[time-nuts] Re: Suggestions solicited for Pi/GPSDO ntp server

On 26/05/2022 17:44, Lee Reynolds via time-nuts wrote: Hi, Lords of Time! (Been a lurker for many years, just know too little to add but am always fascinated by your discussions. It almost reads like theological discursions at some points, it gets into such fine and abstruse points!) I think

[time-nuts] Re: GPScon peogram

On 06/04/2022 00:33, Lon Cottingham wrote:      How does one acquire GPScon?  The only source I find in from Jackson's Labs ant it only works with Jackson Lab's products. 73 de Lon, K5JV I suppose it isn't this program: http://www.realhamradio.com/gpscon-info.htm What about ublox

[time-nuts] Re: GPSDO - GPS1300-10-1000 by RFX Ltd. UK

On 02/03/2022 17:34, va2...@ebox.net wrote: Hello to all members. I want to add to my lab a Pi based display that would show a GNSS SV map like the one attached to this message. Any suggestions ? Thank you ! Claude VA2 HDD Claude, I would look into gpsd. I guess someone will have made a

[time-nuts] Re: GPSDO - GPS1300-10-1000 by RFX Ltd. UK

On 01/03/2022 22:43, Bob kb8tq wrote: Assuming you are south of Hadrian’s Wall, you will have GPS sats overhead at least occasionally. The bulk of what you will be able to “see” will be to the south. If you really have a good antenna location and are a bit north, you may be able to “see” sats on

[time-nuts] Re: electronics question or how not to fry my raspberry pi

On 28/01/2022 19:41, folkert wrote: Hi, [] The RPI doesn't like 5v on its GPIO pins. So I wonder: - can I feed the picdiv 5v on its GPIO pin while giving it a 3.3v voltage so that it outputs 3.3v as well to the rpi pins? - or should I use a voltage divider? I was thinking of a 4.7k ohm and

[time-nuts] Re: Derivation of time from celestial sight

On 27/12/2021 20:18, Brent wrote: My understanding (and I could be wrong) is that one could derive 'stellar' time from a start sight/fix on polaris or another well tracked celestial object. I was once told that early editions of Bowditch provided the process (for the moon I was told) although

[time-nuts] Re: Derivation of time from celestial sight

On 27/12/2021 20:18, Brent wrote: My understanding (and I could be wrong) is that one could derive 'stellar' time from a start sight/fix on polaris or another well tracked celestial object. I was once told that early editions of Bowditch provided the process (for the moon I was told) although

[time-nuts] Re: Poor's man NTP

On 18/12/2021 21:13, giuse...@marullo.it wrote: Hi Bob, If you have a requirement for always being in the microseconds rather than milliseconds, PTP is a better approach. I just need it for logs and computer time sync, PTP seems overkill for my requirements. It is a small lab, then maybe I

[time-nuts] Re: Poor's man NTP

On 16/12/2021 23:37, giuse...@marullo.it wrote: Hi, just wondering if a PI4 could be a suitable NTP server for a small lab (and maybe with some other NTP servers for my company, about 2000 clients). Main use is for correct timestamp on logs/computer time sync. I setup the NTP using Adafruit

[time-nuts] Re: PPS latency? User vs kernel mode

On 13/12/2021 21:22, Trent Piepho wrote: And finally we can have the kernel act on the PPS timestamps itself. But NTP network traffic might be a bridge too far. Mills describes this as a "hardpps()". This was added to Linux in 2011 by Alexander Gordeev, based on Mills' work, but with a

[time-nuts] Re: PPS latency? User vs kernel mode

On 13/12/2021 04:17, Adam Space wrote: What do you mean by "kernel mode"? I am referring to this guide that another user here recommended to me a bit ago. I am not too sure myself since I am relatively new to this. That document is now

[time-nuts] Re: Clock display on Linux systems?

On 05/12/2021 20:53, Adam Space wrote: Most distributions of Linux already have a "clock" application that shows the system time, but I am wondering how to program a more customizable display on a Linux system / Raspberry pi. There are a few solutions that pop up by googling the issue, but these

[time-nuts] Re: Leap indicator set to 1 !

On 27/11/2021 15:22, Steven Sommars wrote: FYI. At 2021-11-27 00:00:00 UTC many public NTP servers began setting the leap indicator to 1. This may be gpsd related Yes, I see it on [possibly] one of my ISP's servers: cpc137586-lock4-2-0-cust263.6-1.cable.virginm.net 86.3.245.8 I wrote

[time-nuts] Re: List Opinion/Suggestion(s)

On 25/11/2021 08:14, Hal Murray wrote: (according to a pre-configured compile-time constant), Have you looked at the tinker stuff in the config file? I'd expect it to be there. I don't see it in there, Hal. David -- SatSignal Software - Quality software for you Web:

[time-nuts] Re: List Opinion/Suggestion(s)

kb...@n1k.org said: I would strongly suggest that with NTP ???more is better???. Three reference devices is about the minimum. Five is a good target to aim for. One suggestion I make to folk who ask is to use the "pool" directive. This allows NTP to choose as many servers as it needs

[time-nuts] Re: NTP servers

On 22/11/2021 02:29, McFail Troll wrote: Hi all, I am new to the mailing list, and pretty new to timing stuff in general. I wanted to ask if any of you folks who have a more advanced set-up (synchronization via gps/radio, or just a well working rubidium clock or something) maintain a solid

[time-nuts] Re: in-ground clock room

On 09/09/2021 03:36, Bill Beam wrote: Tom, How long do you expect your proposed voult to go undisturbed? I have several pendulum clocks. They are disturbed every couple of months by earth quakes. By disturbed, I mean pendulum banging against the case walls Any ground motion that can be

[time-nuts] Re: Comparison/evaluation of u-blox timing receivers

On 24/08/2021 02:51, John Ackermann N8UR wrote: In 2020 I did an extensive evaluation of the timing ability of the u-blox LEA-M8F, NEO-M8N, NEO-M8T, NEO-M9N, ZED-F9P, and ZED-F9T. The work was made possible by support from the HamSci consortium (https://hamsci.org) under NSF grants supporting

[time-nuts] Re: GPS antenna distribution?

On 28/06/2021 21:56, lstosk...@cox.net wrote: Thanks guys. Opened a lot of things to think of. Makes me wonder how I get any results from a north facing window with the UV coating! Will work out something. N0UU Maybe an antenna in the loft might produce better results? Check it with

[time-nuts] Raspberry Pi GPS/PPS/RTC HAT

For UK (and perhaps European) enthusiasts, if the import duty, VAT and collection fee is too great, you might like to look at: https://store.uputronics.com/index.php?route=product/product=60_64_id=81 I hope this is OK to post, but since Brexit buying anything from outside the UK is a lottery

Re: [time-nuts] U-blox F9T performance (was: U-blox teaser)

On 01/03/2021 00:52, Thomas Abbott wrote: Hello Time Nuts, first post from a long-time lurker. In late 2019 I evaluated the Ublox F9T for a project. Here is a graph of the time difference between PPS outputs of two RCB-F9T boards on the bench. Each had a U-blox dual-band ANN-MB-01-00 antenna,

Re: [time-nuts] Raspberry Pi 4 oscillator replacement

On 04/02/2021 10:20, Avamander wrote: Hi, I was wondering if anyone here has replaced the 54 MHz oscillator on the Raspberry Pi 4 with a GNSS-disciplined rubidium standard? An overkill upgrade, but is technically doable? What hardware would it take in addition to a GNSS-disciplined rubidium