Ampegon 100 kW model supports both DRM and analog operation
By James Careless
Radio World – December 18, 2024
Jeff: Last month in the December 18 th edition of the American trade magazine ‘Radio World’, there was an article about Radio New Zealand’s new shortwave transmitter. We realize that some of you will have seen that article already, but
many will not, and since it’s of general interest to shortwave listeners globally, we thought we’d bring it to you here in Wavescan. Here’s Ray Robinson.
Ray: Thanks, Jeff. The article’s byline was by writer James Careless. On August 1, 2024, RNZ Pacific — the international service of New Zealand’s public media organization RNZ — did something rather unusual by current international
broadcasting standards.
Rather than take a shortwave transmitter offline to shut down a service, RNZ Pacific replaced it with a new 100 kW Ampegon TSW-2100 transmitter. As Radio World’s Carter Ross reported at the time, “The new transmitter replaces the 33-year-old
RNZ Pacific ‘Transmitter 1’ installed in 1989 at Rangitaiki, near Taup? in central North Island. Part of a project to improve RNZ Pacific’s capabilities, the new transmitter supports both DRM digital and analog operation.” The estimated cost to the government was US$2.4 million.
Commissioning of the transmitter was officiated by the country’s minister of foreign affairs at RNZ House in Wellington. So why did RNZ Pacific take this step? We asked Chief Technology Officer, Mark Bullen and Transmission Manager, Steve White.
Chartered service
It may seem an overstatement to characterize RNZ Pacific’s installation of a new radio transmitter as a life-or-death decision. But for those in the region who rely on its broadcasts during natural disasters — particularly on small islands with weak
broadcast resources of their own — RNZ Pacific is an information lifeline. This has been especially true since 2017, when Australia cut the last of its international shortwave services to save money.
Fortunately for RNZ Pacific’s far-flung audience, this broadcaster’s shortwave service appears to be safe for the foreseeable future. “RNZ, under its charter, must ‘include an international service to the South Pacific in both English and Pacific
languages,’” said Mark Bullen. As a result, RNZ has been broadcasting on shortwave into the South Pacific region from the Rangitaiki transmitter site since 1990. “Prior to that the service was transmitted from our Titahi Bay site in Wellington, which opened on Monday Sept. 25, 1948,” he said.
To abide by its charter, RNZ Pacific works with media partners across the Pacific to support the reception and rebroadcasting of its content in 22 nations. As well, “as part of our lifeline utility role in New Zealand, we take on the role of
ensuring that we can broadcast lifesaving information to the Pacific region,” said Bullen. “Being able to deliver from outside the region ensures that it can be resilient, regardless of the event impacting the Pacific, whether it be cyclones or
other causes resulting in loss of infrastructure. Since the other nearby shortwave service from Australia ended in 2017, this has reinforced our role as a shortwave service provider in the region.” RNZ Pacific’s decision to include Digital Radio Mondiale capability in its new shortwave transmitter was designed to do more than deliver content to consumer DRM receivers.
“We have media partners that choose to rebroadcast our DRM service within their countries,” Bullen said. “Unlike analog SW, DRM delivers high-quality digital audio that is suitable for rebroadcasting. Thankfully, our existing Thales shortwave 100
kW transmitter also can deliver both analog and DRM services. So this gives us flexibility and resilience across RNZ Pacific’s two transmitters to simulcast if required or to perform maintenance on one of our transmitters.”
RNZ Pacific chose the Ampegon 100 kW transmitter after a ‘request for proposals’ process. “There were two key high-level criteria: commercial viability, and ongoing support and maintenance.” Another transmitter that was considered would have
required structural changes to the transmission building. “Working with Ampegon allowed us to leverage our long working history and support along with the ability to share spares and tubes between the new and old transmitter
Smooth transition
RNZ Pacific’s new Ampegon shortwave transmitter provides the same transmission power as the 1989 Thomson 100 kW analog-only transmitter that it replaced. Listeners are not likely to notice much difference, unless, of course, they are tuning in using DRM digital radios. “The coverage is unchanged, as there have not been any modifications or additions to the antenna system,” said Steve White.
“The gains for RNZ Pacific lie in ensuring that the service is reliable going forward and that we now have redundancy for our DRM service,” Bullen said. Installing and commissioning the transmitter was a relatively smooth process, but some work still had to be done. Specifically, a site control system installed in 2005 was upgraded to interface to the new transmitter and the opportunity was taken to upgrade hardware and software to current versions. The audio distribution system was upgraded to a fully digital system, greatly improving operational flexibility.
Although the Ampegon was essentially a swap-out for the Thomson it replaced, the new transmitter is more efficient. “It also has the AMC analog modulation system, which results in further significant savings on power consumption along with much-reduced stress on the transmitter,” said White. Solid performance The new transmitter is performing as specified. “Now that we have two fully operational transmitters again, we simulcast in analog mode using the second transmitter during our DRM broadcasts so that all listeners can receive the service,” White said.
The old Thomson transmitter has been dismantled, with useful parts recovered for spares. “Parts of the transmitter were also sent to our Titahi Bay transmitter site in Wellington, where they will be put on display next to one of the original 1948
shortwave transmitters,” said White.
The new transmitter appears to be delivering the kind of international reach that the broadcaster was looking for, based on reception reports that listeners send to RNZ Pacific daily as well as data from its own monitoring receivers in the Pacific
region.
“We saw recently that the signal had been picked up by a pocket radio in Plymouth, Minnesota — some 8,000 miles away from the Rangitaiki site,” White said.
“This suggests that the new transmitter is operating well.”
Back to you, Jeff.
(Ray Robinson/Jeff White/Wavescan)
