Know-how

Spreading the Word

Radio Vatican has been spreading Catholic teachings across the globe since 1931. But closer to home, until recently, its antenna pole was spreading something else. Such is its field strength that it was inducing noise in every copper wire in the Vatican. Today, that interference is no longer a problem thanks to a NEXUS at the Vatican.

Not so long ago, Radio Vatican's switching room looked more like a museum than a modern control centre. Sepia tinged photos of its inauguration back in 1931, revealed that little had changed in the room in almost seventy years. Indeed, the microphone pope Pius XI used for the first speech on that inaugural day still exists, and is on public display in the Vatican. So why did the Vatican wait so long before bringing its central technology up to date?

Lack of space

The answer to this question has much to do with the Radio Vatican's unique circumstances, which present specific problems that are unlikely to be encountered by any other broadcaster. For a start, space is limited, so the radio's studios have to lie outside the Vatican, at the Palazzo Pio in Rome. This building hosts a modern computer-networked audio system for recording, editing, and broadcasting. Meanwhile, the transmission pole and the switching room are located on Vatican soil, at the Palazzina, some 3 km inside the city walls. Here, lack of space dictates that the transmission pole and the switching room lie within walking distance of each other.

Until now, programmes recorded and edited at the Palazzo had to be mastered on tape and carried to the switching room inside the Palazzina in order to be aired. A fixed line between these two buildings was out of the question, given the strong noise produced by the transmission antennas: the field strength was too much for conventional analog copper wires to handle.

A Test of Faith

Another drawback was the fact that the antenna has to be rotated, according to the area the broadcasts are to cover. Around noon, the antenna faces the switching room, where all the audio signals are handled – with a radiation efficiency of 80 V/m.

From a theoretical point of view, the Stage Tec crew, however, was confident that even these levels of exposure would pose no problems for NEXUS, and they came to The Vatican to put their faith in the product to the test.

The Vatican borrowed a NEXUS device for four months, and after a thorough series of tests, the system's noise resistance was proved beyond doubt: absolutely no interference or beating could be measured. The only things present were the excellent audio specs of the NEXUS' input stages. The reasons for this are the high common mode rejection of the analog inputs and outputs on the one hand, and the characteristics of fibre-optic cable which is largely immune to electromagnetic interference, on the other.

Networked and Integrated

Today, a fibre-optic line links the studios to the switching room. Either side is equipped with two NEXUS base devices that are connected to each other via Stage Tec's proprietary FOC format. The completed programmes no longer need to be carried physically to the other side, but are now simply sent down an optical line. The Vatican uses mono-mode cable for bridging the distance of several kilometres.

Apart from linking the production centre to the switching room, NEXUS also handles several other tasks: for example, it distributes the various signals and converts them into different formats in the studio complex as well as in the switching room. In comparison to the old system, NEXUS has allowed the Vatican to save up 80% on cable runs, with the additional advantage that the NEXUS can be controlled by the on-air system with a precision of less than a second. Furthermore, the NEXUS' controlling PCs have been integrated into the production network. The multiuser software and graphic user interface run on the same computers that are also used for recording and editing the radio's material. Finally, the XDSP plug-in boards connected to the NEXUS also handle processing of the broadcast signal's dynamics, thereby rendering the station's former 32 limiters obsolete.

New Beginnings

For the planners at Radio Vatican, it was an undeniably big decision to carry out such a momentous overhaul, involving the replacement of tried and tested equipment. A great deal of preparation was required, as well as the support of all those in charge at the station. Florenzo Petitta, the technical production manager, Piero Iorio, the technical manager of the switching centre, and Maurizio Venuto, the technical director of Radio Vatican, jointly voted in favour of NEXUS. However, don't expect the NEXUS system to remain unchanged for another seventy years. On the contrary, such is the success of the new system that plans are already underway for the first expansions of the system in the shape of additional base devices.

Radio Vatican Today

According to Radio Vatican's multilingual information pack, its main aim is »to link the heart of the catholic world with all countries around the globe«. Back in 1931 programmes were broadcast in Latin, to a limited audience. But today, Radio Vatican broadcasts in 53 languages, and to 32 different territories of the world. The huge programme offering is prepared by 60 engineers in 14 control rooms, and countless reporters and journalists working in all the various languages. Broadcasting on short wave, medium wave, FM, and via satellite – Radio Vatican truly covers the world.