NEW ZEALAND AND AUSTRALIA TIME RESOURCES

If you can help us with additions, corrections, new links, please contact us.
The address is on the NZ&A Time home page.


LONGWAVE (LF) RADIO STANDARD TIME SIGNALS
SUPPORTING 'SELF-CORRECTING' CLOCKS


Available in Europe, USA, Japan  -  but  at present NOT normally usable in New Zealand or Australia, although in 'some' circumstances these clocks may 'perhaps'  'just' manage to operate (see reported examples below).

In many regions of the world, Governments provide a low frequency (LF) Standard Time signal at below the old "Long Wave" band.  These transmissions are in the range of  40 kHz  to  162 kHz, with 60 and 77.5 kHz being the most common.  A typical example is  WWVB on 60 kHz in the USA; others are in Japan  JJY on 40 kHz and 60 kHz,  the United Kingdom  MSF on 60 kHz ,  Germany  DCF77 on  77.5 kHz  (information in German), and others in Switzerland  HBG on  75 kHz  (in English, German, French and Italian!)  and  France  TDF on 162 kHz (in French).  Some other, unusual stations are listed in the  Station Lists Compiled by William Hepburn, LWCA .

From information on the web sites of some of these stations their nominal useful range is of the order of 2000 to 3000 km so that WWVB covers all of North America, DCF77 covers all of western Europe, etc.   Also refer to  David Mills' excellent site with information on Time and Frequency Services

These signals are provided because there is a world wide mass market for low cost  "Radio Controlled Clocks" and watches, often termed  "Atomic (accuracy) Clocks/Watches", which automatically synchronise themselves to these LF signals.  Such self-correcting clocks are extremely useful in schools, offices, etc. because they also adjust to daylight saving switches, leap seconds, and recover nicely after power outages.  Typically, a 'radio controlled clock' will synchronise itself a few times each day (e.g. every 6 or 12 hours), or upon user request, and at other times keep running as a normal quartz clock.  The LF band has the advantage that its waves penetrate deep into buildings, making for almost "universal" coverage in those regions where transmitters exist.  In practice, clocks working at  60 kHz and 77.5 kHz are widely used.

If you were to purchase one of these clocks please consider whether it will receive the most common frequency in your Region.  Some clocks (e.g. SEIKO Global Wave) can automatically search at both 60 kHz and 77.5 kHz to serve all their world markets.  However, other brands produce different models for 60, 75 or 77.5 kHz.  For example, Oregon Scientific and Sangean produce clocks for 60 kHz for the US and British market, and different models  (with different model numbers) receiving 77.5 kHz for continental Europe.  A number of Swiss companies produce models for 75 kHz which is used only in Switzerland.  A strange situation because Switzerland is well within the range of German DCF77, and HBG and DCF use the same time code.   France, too, is following its own course.........

We see these "atomic clocks" advertised in international publications, even in Australia (see lower on this page) and may be tempted to buy them in Duty Free shops in overseas Airports, but  because there are no transmitters in New Zealand or Australia these clocks should not be expected to automatically adjust in our region. 

SURPRISE  -  SOMETIMES THEY DO WORK HERE......

However, in July 2005 we received a report on a 'Seiko World Global Radio Wave Control Radio' from Perth, Western Australia:

Subject: JJY 60 KHz
Thanks for your interesting home page.    -     I'd thought you would be interested to know that my SEIKO world global radio wave control radio, purchased in Japan very recently, is receiving (but not every day) a signal here in Perth WA showing JPW (i.e. Japan West), namely JJY 60 kHz!  The angle of the clock can affect reception (and some times I see it cycling through the British, German, Japanese and US stations without result, so it must be a very weak signal).   I set it at -1 hour and it shows deadly accurate time Perth WA time!  Have you had any other reports like this.  I can't find anything else on the web for about this for Australia.

SURPRISE  -  SOMETIMES THEY DO WORK HERE......

And in July 2006 we received the following report from a travelling user in Scotland and New Zealand:

<>I have been visiting your website because I was hoping to get some clarification of a rather strange phenomenon.  I own a watch which synchronises with the DCF77 signal from Mainflingen in Germany.   Being based in Scotland it never fails to obtain the signal at 1 am in the morning.  If the watch cannot obtain a signal, as was the case when I went to southern Africa, it starts counting the days from when it obtained the signal last.  On my recent trip to Christchurch, NZ, I did not expect to receive any synchronisation signal - not only because of the distance but also because all other international time signal broadcasts are done on a different frequency.  I was very surprised to note that my watch seemed to obtain a signal but always with a one-day delay.  Throughout our 6-week stay it showed 1 day (instead of the normal 0), during our flight back home it went up to 2 and finally went back to 0 after it re-synchronised back home.  I was wondering  if there might be a logical explanation for this behaviour of my watch in NZ.  The above report  raises the questions: was this particular watch able to receive 60 kHz, as used by JJY and WWVB (in addition to its "listed" DCF77?   If it was using WWVB, would that explain the one day offset?  Or is there another explanation?

SURPRISE  -  SOMETIMES THEY DO WORK HERE......

Report of a 'Casio Ceptor' working in Melbourne in mid 2007:   

When I asked him why my Casio Ceptor watch was functioning perfectly, he told me what you say in your website; Australia does not have a 60 kHz WWVB format signal.  On Friday the 22nd of June 2007 I received my new Casio Ceptor in the mail. I turned it on at 6:30 pm. The watch was able to figure out the date straight away. Then the analogue hands started swirling around and stopped at the wrong time (but the minutes were correct). In timekeeping mode I held down button A for four seconds to get GMT differential value. I adjusted this from GMT+4 to GMT +10. The analogue hands started swirling around again, stopping at the right time and started ticking away happily.   The closest signal to Melbourne is Japan. As the two Japanese radio stations coverage is small enough that they need two stations to cover their archipelago, Melbourne seems like an awfully long way. I would certainly like to hear your thoughts on this. Much as  would love to own a Suunto with GPS that can pick up signals from satellites, money prohibits. How far is it from Melbourne to Japan? I look forward to your reply.

SURPRISE  -  SOMETIMES THEY DO WORK HERE......

Report on a 'Citizen Skyhawk' from Brisbane in March 2008:

<>A week ago i received my new 'Citizen Skyhawk A-T' atomic timekeeping aviation watch from the USA. I am a pilot in Australia and purchased this watch for its aviation uses not for the atomic clock time keeping functions as I new Australia had no atomic transmitters.  Having set the watch up it now receives a low to medium signal strength from JJY everyday. I can press the signal strength test button at any time and it will show JJY as the transmitter it is receiving from and with a signal strength of L-M.  This is great to know as for obvious reasons the watch will be able to maintain its accuracy.

YOUR NZ - AUS USER FEEDBACK IS WELCOME

For example, is it possible that these clocks may in fact work in the North Island of New Zealand or the State of Queensland in Australia
???   And - if so - is there a way to work out whether the device is using a "fringe" signal from JJY Japan? or from WWVB, US???    -  please advise

YOUR NZ - AUS USER FEEDBACK IS WELCOME


A Note of Caution on the accuracy of LF Clocks

There is some well-informed discussion in the USA and Japan of these Low Frequency ("Atomic") clocks in the IOTA Occultations email group:     http://groups.yahoo.com/group/IOTAoccultations/
It has been noticed by some observers that when these clocks synchronise themselves against the LF transmission, they may still be a small but significant deviation from correct time of the order of a few tenths of a second.  Such small differences will not be noticed by the average home or office user, but they are a serious problem if these clocks were to be used for scientific work.

For example, please note this paragraph from a post (No. 3864) on this Group by Mitsuru Soma on 6 February 2003:

"I examined such cheap clocks sold here in Japan, that are set with the Japanese JJY longwave time signal broadcasts of 40 kHz and 60 kHz, and found that they have delays of about 0.1 sec to 0.3 sec with respect to the time signals even just after the automatic adjustment, as noted in Occultation Newsletter (August 2000, Vol. 8, No. 2, p.4).  An engineer of clock maker Casio also admitted that their radio clocks and watches have delays of about 0.2 sec when the automatic adjustment is made.  So check the accuracy of your 'atomic time clocks' before using them for your observations."

These delays may (?) or may not (?) be present in clocks manufactured by other companies  in other countries, but it is essential that their accuracy be checked.


Despite the above, these clock are often sold in Australia.  The wise buyer beware....

In Australia, the National Time Committee has in the past considered establishing such an LF standard time station, but to date this has always been rejected on the grounds of cost.  Despite this, occasionally such LF clocks are sold in Australia by over-zealous marketers.  For example, in early 2002 this occurred in the  "Australian Geographic" chain of shops, when they advertised such "Radio Controlled Clocks" for sale, which were subsequently withdrawn from the catalogue when it was found that there is no suitable signal available in Australia.   Again in May 2003, "Australian Geographic" included in their Winter Catalogue the "Oregon Scientific Projection Barometer", with the product description:  "A multifunction, RF- controlled projection calendar clock that automatically synchronises current time and date."   Upon contacting "Australian Geographic" we were advised that:   "the clock will work within 1,500 kilometres of the DCF transmitter".  Because the DCF transmitter is in Germany, this too far from any users in Australia or NZ.  While it is probable that such a clock module could also use the LF signal from e.g. the Japanese equivalent transmitter, this is unlikely to be of sufficient strength in the south Pacific.  In 2006 it was found that both Dick Smith and David Jones sold a range of Oregon Scientific clock suitable for DCF77, but their packaging correctly advises the purchaser that the radio control function will not operate in Australia.

Since then such clocks keep popping up in shops in Australia.  Sometimes with a small sticker on the box advising that the automatic setting will not work here, but more often without any advice.  It seems most people buy such clocks because they like the 'style' or 'design' and don't worry about whether they keep time.

Until the standards organisations in our region can make governments decide to build suitable transmitters, these LF synchronised clocks can generally not be expected to work reliably in New Zealand or Australia, although you may just be (very) lucky.......
 

Click here to return to the N. Z. and A. Time Home Page