If you can help us with additions, corrections, new links, please
The address is on the NZ&A Time home page.
Short Wave radio -
Short Wave Radio Standard Time signals have long been a favourite tool for scientific workers and observers at field sites, where medium accuracy time is needed, to be recorded continuously. At times of good radio propagation, any simple radio with a SW band can be used to pick up a usable signal. In addition to time pips, the SW signal usually also gives voice or coded time (Hour and Minute) information and station ID. The most suitable source of standard time signals in the South Pacific is WWVH, broadcasting from Hawaii.
An interesting note on the 'as
of time signals, far away from their transmitter site, can be found in
archived post by Art Lucas
on the IOTA Occultations email group at: http://groups.yahoo.com/group/IOTAoccultations/
In practice, the WWVH signal from Hawaii can be used for (visual,
manual) basic timing tasks as far away as Australia with a propagation
delay of the
order of 0.05 second (approx. 50 ms).
|Also see the note below on a local group in New Zealand with interest in time on HF|
VNG (Australia) died on 31 December 2002 at 23:43:43 UTC
VNG was inaugurated by the Australian Post Office on 21 September 1964 at Lyndhurst, Victoria, and operated on 4.500, 7.500 and 12.000 MHz until 1 October 1987, when transmissions were terminated. It was then moved to Llandilo, New South Wales, where the first transmission took place in June 1988. The service from Llandilo continued until 31 December 2002. In the last period of operation, standard time signals were available on 5.000, 8.638, 12.984 or 16.000 MHz (daytime only) short wave. A full description of the later Station, its history and details of broadcast codes and format can be found in National Standards Commission information leaflet "Radio VNG".) If you would like to hear the last minute of VNG transmission on 12.984 MHz, please check this MP3 sound file. The last second marker was at 23:43:43 UTC
When VNG was still available, the receiving equipment could be any cheap old analogue (second hand shop) battery operated portable. Since the closure of VNG on 31 December 2002, the SW time signals available in the South Pacific have to travel from Hawaii, mainland USA, Canada or China. The received signal strength in New Zealand and Australia is lower and more variable than that from VNG, making reliable reception more difficult. In good conditions, however, the WWVH signal strength can still be remarkably good for a few hours. To improve the performance of your receiver, it is worth experimenting with long and short extension aerials. Try different antenna compass orientations, and stay away from power and cable TV cables and electric fences, all known sources of noise and interference. Short Wave radio can still be a useful, adequate, low cost entry point into fairly respectable timing.
There is an excellent up-to-date Time Signal Stations Frequency List by Klaus Betke. Also refer to David Mills' excellent site Information on Time and Frequency Services
WWVH (Hawaii) and WWV (Colorado)
WWVH and WWV broadcast on the international time standard frequencies of 2.5, 5, 10, 15 and 20 (WWV only) MHz. In New Zealand and Australia 5 and 10 are the best at night, 10 and 15 (on rare occasions also 20 MHz) in the daytime and early evening. Mostly, WWVH is received at the best signal strength, with WWV faintly in the background, but at times WWV is almost as good. WWVH is a extremely reliable and respected service. The Hawaiian service started in 1948 and between 2000 and 2007 a full set of new technology fibreglass encased antennas was built on Kauai, suggesting that the service is to continue for the coming years.
(Currently, in 2002, there appears to be a severe interference problem in Western Australia with many Indonesian fishing vessels using 10 MHz as their communication channel, ignoring international regulations. This "chatter" is noticeable as far as South Eastern Australia, but WWVH is mostly still "usable" there.)
On WWVH and WWV the seconds pulses are heard every second except on the 29th and 59th seconds of each minute. The first pulse of each hour is a long 800 ms pulse of 1500 Hz. The first pulse of each minute is a long 800 ms pulse of 1000 Hz at WWV and 1200 Hz at WWVH. The remaining seconds pulses are very short audio bursts (5 ms pulses of 1000 Hz at WWV and 1200 Hz at WWVH) that sound like the 'ticking' of a clock
The voice time announcements (female for WWVH, male for WWV) are
each minute, other space and earth weather information, geophysical
alerts and GPS satellite status reports are broadcast at
times. For timekeeping ignore the ongoing continuous tones on
which are often heard from second 1 (i.e. the tones start one second
the full minute) until second 45. The complete format
of the WWVH and WWV time codes can be found at the NIST web site:
|*** WARNING *** Can you sometimes hear
confusing 'double' or
'twin' second markers ?
Do these occur during the minutes 25 - 29 and 55 - 59 ?
For example, on WWVH, do you hear: - - - - - tick pip - - - - - tick pip - - - - - tick pip - - ?
This is caused by the Chinese BPM ‘UT1’ time pips - Check This
Because the signals from WWVH and WWV are often weak, there is a likelihood of interference from other standard time stations on the same international frequencies of 5, 10 and 15 MHz. Most of these are no problem, because they also transmit UTC and are usually much weaker. One of these is standard time station ‘BPM’ in Pucheng, China, which is operated by the Chinese National Time Service Center (NTSC) (Shaanxi Astronomical Observatory, Chinese Academy of Sciences). Like other standard time signal stations, most of the time BPM transmits UTC.
However, during the minutes 25 - 29 and 55 - 59, station BPM transmits UT1. Ref: Time Signal Stations Frequency List by Klaus Betke. This is a complex issue, because the difference (DUT1) between UT and UT1 can be positive or negative, and can be up to 0.9 sec. As a result, the BPM UT1 'pips' can be before or after the WWVH UTC 'tics'. If you encounter this problem with these two stations, then luckily they can be separated because the WWVH and WWVH second markers are 'ticks', and the BPM pips are 'beeps'. At present (January 2009) DUT1 is about 0.4 seconds. Check this NIST web site for up to date information: http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm
The identity of station BPM can be confirmed by listening
the last minute of the hour, just before the full hour, when a female
(Chinese) voice speaks the words: "B P M ,..... B P M ,..... B P M
,.....". And, to confirm this further, the 'double' pips
should disappear on the half
or full hour. Repeat: this paragraph only applies to the UT1
during minutes 25 - 29 and 55 - 59.
To overcome this problem, try one of the other WWV(H)
CHU (Ottawa, Canada)
At times, on the 'non-standard' frequencies of 3.300, 7.850 and 14.670 MHz, Canadian Standard Time Signal Station 'CHU' can also be received for a few hours in the South Pacific. NOTE: 7.850 MHz is a new frequency that is being used as of January 1, 2009. The old frequency of 7.335 Mhz was within the expanded 40 metre international broadcast band (7.200 - 7.350 MHz) as decided by the International Telecommunication Union (ITU) in 2007. Indeed 7.850 has been heard in South-Eastern Australia in early January 2009, but it is found that WWVH on 5.000 is stronger at those times.
On CHU the 29th and 51st to 59th Second Markers
are omitted, and alternating bilingual voice announcements of local
(not UTC) are made between seconds 50 and 59. There are further
time codes built into this signal between seconds 31 and 90 - for
see the Klaus Betke site. However, we find that: if CHU is
WWVH or WWV are most likely stronger, and preferred for their easier to
time code system. Also Hawaii (the source of WWVH) is closer to
New Zealand and Australia than Ottawa, so that there is less
POSSIBLE INTEREST IN HF TIME DISTRIBUTION IN NEW ZEALAND
An amateur radio group in New Zealand has access to very respectable time generating and low power HF transmitting equipment.
More details on the we site http://www.qsl.net/zl1bpu/micro
which is maintained by Murray Greenman
ZL1BPU Please contact Murray directly for
technical enquiries, expressions of interest
and offers of support.
For Domestic FM / AM radio stations in New
Please follow this link to the Broadcast Page
Do not use time pips on International SW
broadcast stations (e.g. the BBC)
Do not rely on time signals on large International SW broadcast stations (e.g. the BBC, RN, DW), which broadcast time pips on the full hour. The problem is that these SW (HF) broadcast programmes are distributed around the world using extremely long paths and variable networks that often include satellite links which add very large delays. As received, they can be significantly delayed. An exception is Radio New Zealand International (RNZI), as this only has one local transmitter. The signal from RNZI is therefore similar to that from the regular NZ National Radio - please refer to the notes there.