Re: [time-nuts] leapseconds, converting between GPS time (week, second) and UTC

Yes of course you are right. NTP timebase (based on UTC with an epoch of 1900-01-01 00:00:00, or its representation in Unix time - seconds since 1970-01-01 00:00:00) is timezone independent. I just wanted to make the point that in the IT world (I've worked for Amazon, Microsoft, Twitter and now I

Re: [time-nuts] leapseconds, converting between GPS time (week, second) and UTC

NGFUL ANSWER." On Wed, Jan 16, 2019 at 9:01 AM Martin Burnicki wrote: > > Fiorenzo Cattaneo wrote: > > Yes of course you are right. NTP timebase (based on UTC with an epoch > > of 1900-01-01 00:00:00, or its representation in Unix time - seconds > > since 1970-01-01

Re: [time-nuts] NTP's discontinuity (it isn't) (was Re: leapseconds, converting between GPS time (week, second) and UTC

ing before using any library which claims to be leap-second compliant. -- Fio Cattaneo Universal AC, can Entropy be reversed? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER." On Wed, Jan 16, 2019 at 7:00 AM Peter Laws wrote: > > On Wed, Jan 16, 2019 at 2:01 AM Fior

Re: [time-nuts] leapseconds, converting between GPS time (week, second) and UTC

? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER." On Tue, Jan 15, 2019 at 12:25 PM Fiorenzo Cattaneo wrote: > > I double check the Python code, and I can confirm it does not take > LEAP seconds into account. I highly doubt you will find standard time > libraries for the

Re: [time-nuts] leapseconds, converting between GPS time (week, second) and UTC

I double check the Python code, and I can confirm it does not take LEAP seconds into account. I highly doubt you will find standard time libraries for the most common languages which will deal with LEAP seconds. They would rather just ignore it and have one less of a headache to worry about

Re: [time-nuts] time-nuts Digest, Vol 184, Issue 11

Completely agree, this is great work. Very original thinking. -Original Message- From: time-nuts On Behalf Of Dave B via time-nuts Sent: Friday, 8 November, 2019 01:36 To: time-nuts@lists.febo.com Cc: Dave B Subject: Re: [time-nuts] time-nuts Digest, Vol 184, Issue 11 Nice work.

Re: [time-nuts] Raspberry Pi 4B Ethernet delay

Well, yes and no. The speed of light is course always the same, but in case of ethernet the latency is determined by the time it takes for the packet to be transmitted at a given bitrate , plus switch delays, and output / input delays on the ethernet controller as well as the software

[time-nuts] n00b contribution -- WWVB software for EVERSET ES100 dual-antenna receiver

Hello everyone, this is the first time I actually make a modest n00b contribution to time-nuts, so please be kind with me  I will appreciate any comments, criticism and suggestions. Aside from GPSDO and Rubidium Oscillators, I am also quite interested in radio clock receivers. So I found the

Re: [time-nuts] can of worms: time-of-day in a community radio station

authority for time, or at least one which is not easily spoofed or hacked. -- Fio Cattaneo Universal AC, can Entropy be reversed? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER." On Sun, Nov 3, 2019 at 8:00 AM Attila Kinali wrote: > > On Sat, 19 Oct 2019 18:24:57

Re: [time-nuts] can of worms: time-of-day in a community radio station

Here are (some) answers to your questions. Using NTP to synchronize time across all machines is the one which makes the most sense IMHO. In the past I setup the NTP server architecture for a "megacorp" I was working for, and I have replicated the same setup (at a much smaller case) in my house.

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi David, I don't particularly trust NTP servers from pool.ntp.org (I assume that is what you mean by "pool"), and I use public stratum-1 servers chosen from a public list. Of course I make sure that my usage complies with the policies and terms of use for each server (some allow regional use

Re: [time-nuts] can of worms: time-of-day in a community radio station

I have been quite puzzled about the asymmetric nature of my home Cable Modem connection to the Internet in regard with the offset discrepancy I observe. The "last mile" asymmetric nature of Cable Modem (Comcast in my case) is not very high compared the delta I see between my stratum-1 servers at

Re: [time-nuts] Do ordinary clouds adversely affect GPS reception?

Any kind of atmospheric disturbance has a measurable effect on GPS space and time precision, the question is more about how much the impact is. Presuming that the GPS receiver is stationary, the antenna has a clear visibility of the sky, then "ordinary weather" like clouds, moderate rain or snow,

Re: [time-nuts] GPSDO+PC as a NTP server

I also have a BG7TBL, version 2019-03-25, and I use it with a small embedded X64_64 pcengines box with a dedicated mPCI RS232 receiver. See picture attached, the PCENGINES box is the black box below the GPSDO. > > 1. The GPS chip onboard can be set via RS232C, for instance by u-center > program.

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hello David, >>> I'm surprised you don't trust "pool" servers. My experience is that using >>> the pool directive, and allowing NTP to expand its server list automatically >>> to the maximum number of servers, gives good results usually with one of two >>> servers at least being stratum-1

Re: [time-nuts] can of worms: time-of-day in a community radio station

I'd definitely think so, good idea :-) . I've also seen some open source projects which calibrate the PPM drift based on the measured temperature either using the CPU's temperature measurement or a cheap USB temperature ambient sensor, thus implementing some sort of "software ovenization".

Re: [time-nuts] can of worms: time-of-day in a community radio station

> > > With this setup you have no single point of failure, and even if the > > connection to internet fails, they can still provide time as they are > > peering > > and synchronizing with each other. > No, it doesn't work that way. You need connectivity to at least one stratum 1 > server. >

Re: [time-nuts] Do ordinary clouds adversely affect GPS reception?

vanilla receiver? Apologies for the many questions. -- Fio Cattaneo Universal AC, can Entropy be reversed? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER." On Tue, Oct 22, 2019 at 6:06 AM jimlux wrote: > > On 10/22/19 1:13 AM, Poul-Henning Kamp wrote: > &g

Re: [time-nuts] can of worms: time-of-day in a community radio station

be reversed? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER." On Mon, Oct 21, 2019 at 12:06 PM Achim Gratz wrote: > > Fiorenzo Cattaneo writes: > > I have been quite puzzled about the asymmetric nature of my home Cable > > Modem connection to the Intern

Re: [time-nuts] Garmin 18x GPS WNRO, revisited

The Garmin 18x I have still works, and I verified it works after a power cycle. I'm running firmware version 4.40. Apparently all the 4.XX firmware versions are related to GPS week rollover fixes. Earlier versions also have fixes for "improved" time keeping. Here is the download link for 18X:

Re: [time-nuts] GPSDO+PC as a NTP server

Cattaneo Universal AC, can Entropy be reversed? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER." > On Oct 30, 2019, at 02:02, Adam Kumiszcza wrote: > >  > HI again! > >> On Wed, Oct 23, 2019 at 9:37 PM Fiorenzo Cattaneo wrote: >> > 2. I wo

Re: [time-nuts] NTP apps on Windows question

Yes you definitely need to disable and stop windows builtin ntp client. -- Fio Cattaneo Universal AC, can Entropy be reversed? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER." > On Sep 24, 2019, at 14:35, Chris Burford wrote: > > Yes, > > You want to disable Windows Time

Re: [time-nuts] Daft idea with the National Grid

I remember when studying covert channel communication (as part of computer security) that during the cold war one of the ways you could transmit very low bit rate data (1 bit per minute or slower) was by modulating the power consumption of an industrial plant, something that a spy would be easily