The 'landline' networks also have significant (and variable) latency. ISTR measuring a maximum of around 400/500 mSec some years ago on a WN-CH digital link. Minimum over the test period of a week was nearer 250 mSec a few days later. DaveB ChCh, NZ
-----Original Message----- From: time-nuts [mailto:[email protected]] On Behalf Of Will Kimber Sent: Monday, 2 January 2017 1:01 p.m. To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] new year crashes Geoff I have also noted the pips sound different and seem to recall an on air comment about using local time*. The last pip is not always longer. You have also got to watch out for them using off air Freeview satellite transmissions rebroadcast on normal radio stations! Cheers, Will ZL1TAO * Maybe from the Carter Observatory where the old solar transit was. I'm not suggesting that they use it still. On 01/02/2017 12:46 PM, Kiwi Geoff wrote: > Will Kimber <[email protected]> wrote: >> If you listened to Radio New Zealand National news New Year's day >> morning you would have heard then stating there will be 7 pips at 1:00pm. >> >> However there were only 6 !!! So what happened? > I was listening to both of the above events too, and agree with your > comments Will. > > The following is just my "observations" over the last few years as a > keen RNZ listener, and so may not be correct to those in the know. > > To my ears, there are two "types" of Time Pips: > > The "normal" time pips sound like reasonably pure sine-waves of 1KHz, > and are always correct to my house standard, and would be derived from > the atomic clocks at: > > Measurement Standards Laboratory > Callaghan Innovation > PO Box 31 310 > Lower Hutt 5040 > New Zealand > > https://www.msl.irl.cri.nz/services/time-and-frequency > > The "other" time pips sound different, they appear to be shorter in > duration and more like a square-wave at 1KHz than a sine-wave. I > assume they are locally generated at RNZ and are used when the > land-line to Lower Hutt is broken by road-works, earthquakes, or a > digger driver with a careless hand ! > > In the past I have detected the "other" time pips drifting by about > half a second per day, so I assume it's a relatively simple XO that is > used rather than a GPS which I thought would have been a better option > for a standby reference. > > So my guess as to what is currently going on (for RNZ time pips) is > that they are using the backup system , which appears to be manually > set - and is yet to be manually set by a man! > > Maybe someone who knows someone in RNZ engineering, can give a more > accurate picture than just my conjecture. > > Regards, Geoff ( Christchurch, New Zealand ). > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
