Technical Information
Our studios are located in down-town Wellington. At the start of 2000 we moved to a new digital system which has almost completely replaced tape for all programme making and broadcast tasks.
Technical Manager
Adrian Sainsbury
New Digital capable (DRM) Shortwave Transmitter in 2005/06
In May 2004 New Zealand’s Minister for Broadcasting announced a funding boost for Radio New Zealand International.
The Government is to provide additional funding to RNZI in 2005 – 2006 for a new digital capable (DRM) short-wave transmitter. Radio New Zealand International currently has just one analogue transmitter and it is nearing the end of its serviceable life.
Commenting on the funding announcement, Radio New Zealand Chief Executive, Peter Cavanagh, emphasised the importance of the Radio New Zealand International service:
“ The new transmitter will secure the long term future of what has become a vitally important service to the people of the Pacific region. This very welcome funding recognises the significant part played by Radio New Zealand International in increasing understanding and awareness of New Zealand’s role in the Pacific. “
Radio New Zealand International Manager, Linden Clark, says the Government announcement is a great boost for the broadcaster.
“This announcement means that programming can be delivered to the Pacific via a high quality signal ... it’ll sound like FM. We’ve known for a long time that our Pacific content is the best there is – and now we’ll know that our delivery system can match it.”
The new transmitter will work alongside the existing RNZI transmitter and ultimately replace it. It will used in its digital mode to deliver relaying Pacific stations with their daily RNZI news and programmes for broadcast around the region. The new transmitter can also be used in an analogue mode.
It is expected that the new transmitter will be in service by the start of 2006.
RNZI Antenna
We operate two high frequency and two low band antennae manufactured by T.C.I. of California. One of each beams 35 degrees and one of each beams 325 degrees. They can be driven individually, or when fed in parallel the beam widens to 140 degrees.
HR
2/4/0.5 is a five band curtain antenna with a frequency
range of 9.5 to 17.9MHz.
It consists of 8 folded dipoles arranged in two columns of four dipoles. The average angle of elevation is 10 degrees and the gain is 17db at 9 MHz which gives an ERP of two megawatts rising to 20 db at 17MHz which gives an ERP of five megawatts in broad terms. In March 1993 the low frequency antenna was installed.
If you wish you can click on the picture for a larger image.
HR 2/2/1 is a four band dipole curtain antenna with a frequency
range of 5.95 to 12.05 MHz.
It consists of four dipoles arranged in two columns of two dipoles. The average take-off angle is 12 degrees with a gain of 16 db at 6 MHz increasing to 19 db at 12 MHz. The antennas are fed with 300 ohm open line feeders with a complex matching and switching system.
A large reflecting mesh forms a backdrop to each antenna array and the tension on the dipoles is maintained with a system of pulleys and counterweights.
The 35 degree beam covers the South Eastern Pacific, and North America. The 325 degree beam covers the South Western Pacific, NE Australia, Japan, China and Europe.
With the antennae combined, virtually all the Pacific Basin is covered.
This map gives a general
view of the target area covered by Radio New Zealand International.
Clicking on the the map will open a larger version in a new window.
RNZI Transmitter
Our transmitter is sited at Rangitaiki, 41km east of Taupo in the centre of the North Island of New Zealand. The transmitter coordinates are 176.25E and 38.50S. Audio is fed to the transmitter by a digital link from the studios in Wellington, 400 kms south of Taupo.
The transmitter was manufactured by Thompson CSF of France and installed in 1990. It has an output power of 100kw and is equipped with three transmitting tubes; 2 x TH581 with hypervapotron cooling and one TH581 with air cooling. The station broadcasts 15 hours a day, and the frequency is changed at intervals so as to maintain a strong signal in the Pacific region.
It includes a control and telemetry system operating through a standard RS232 computer port. It is unmanned and is controlled from our Studio in Radio New Zealand House, Wellington. The transmitter is single sideband capable and has Dynamic Amplitude Carrier Modulation as standard.
It is frequency agile, and can be tuned automatically to any frequency in the HF broadcast bands. Dynamic Amplitude Carrier Modulation is a system designed to reduce power costs by reducing the carrier level transmitted to a level necessary for demodulation of the received signal. A number of international broadcasters are now retro-fitting this system to older equipment to obtain power savings. The main features of the transmitter are:
- high level modulation of the final RF stage due to DMP (Duration Modulated Pulses) modulation;
- outstanding operational flexibility due to the option of several modulation systems including SSB and AM stereo;
- high performance frequency slaving for 100 preset frequencies, or
automatic tuning to any frequency in the broadcast bands.
