Radio/Television BEOGRAD… on the move 

18 October 2021

RTB Selects RCA


An RCA OB unit

The RCA/RTB mobile van at Montreux… open house at the latest color television studio on wheels


RCA Broadcast News cover

From RCA Broadcast News for March 1972

Radio-Television Beograd (RTB) is Yugoslavia’s largest TV station and is one of the six virtually autonomous television stations in the country (each serves one of the Republics of Yugoslavia).

They are completing a station expansion program that will permit them to provide high-quality color telecasts of topics of national interest, such as sports, cultural affairs, community meetings and other activities originating either in their studios or elsewhere in the Republic of Serbia.

They will also be “mobilized for color,” because the new studio complex will be complemented by their first color mobile unit—one of the most sophisticated OB (outside broadcast) vans ever built.

In July, 1970, a contract in excess of $1.5 million [$10.5m now allowing for inflation] was awarded to RCA, covering equipment for the new studio complex in Belgrade and a mobile telecasting unit. Although the permanent studios are still under construction and will not be fully operational until December of this year, the van went into service recently and has already added a new dimension to the station’s daily bill of fare.

From Ohio to Belgrade In 200 days

Physically, the mobile van is a “true” bus configuration, 10.7 meters long, 2.4 meters wide (overall) and 3.8 meters high (measured from road surface to roof). It is powered by a GMC V6 engine, generating 254 gross hp. The custom-built body was fabricated by an RCA sub-contractor in Ohio within 120 days from chassis lay-out. All equipment installation and final checkout was accomplished in 37 days at the RCA Custom Repair and Engineering Shop in Pennsauken, New Jersey (220 Bldg.). When it was finished and reviewed by the customer, who was in the United States for final acceptance tests, the van had to be delivered to RTB, so its journey to Yugoslavia from RCA 220 Building was in itself quite a feat.

The first destination in the journey was the 7th International Television Symposium and Technical Exhibition, Montreux, Switzerland, in May where it was exhibited with the permission of the customer. From Pennsauken the van was driven to the Port of Newark, New Jersey, where it was transferred to a “containerized” vessel bound for Bremerhaven, Germany. A railroad flatcar brought it to Basel, Switzerland, and then it was driven, over 160 Km of mountain roads, to Montreux to become one of the major attractions at the RCA Pavilion. After the 10 days of the show it departed on the 1,700-Km journey to Belgrade, where it arrived on June 5. From Ohio to Belgrade it had traveled more than 10,000 Km.


Four tiny monitors under a flap on the outside of the OB van


Equipped for complete color operation

The heart of the van is its complement of four TK-44A color cameras, each of which is equipped with zoom lens, exclusive RCA “Chromacomp” color control module and all of the other characteristics and technical capabilities that have made it a leader in the broadcast industry. The TK-44A’s feed a TS-51 production video switcher that has built-in capability for over one hundred special effects.

At the front of the body, a complete audio control center features a BC-100 audio console that permits the control and mixing of 36 microphones and 25 high-level inputs into 4 separate and/or simultaneous output channels. Two independent outputs are available to drive separate reverberation units. In addition it has a built-in, multi-frequency test oscillator that can be switched into any input or output and a fold-back output channel. Audio tape recording and playback facilities include two RT-21 reel-to-reel machines and an RT-16 broadcast cartridge player that provides six simultaneous and independent program channels. The tape machines are installed in a rack that also contains full patching and monitoring units. The audio compartment, video director’s console, cameramen, CCU’s, external video tape van(s) and support areas, such as lighting director and assistant, floor director and assistant and commentator, are interconnected with the new BCS-5000 intercom system to ensure continuous coordination. The BCS-5000 offers both selective and multiple station call. Communications between the van and the studio complex in Belgrade are maintained by a “Super-Carfone” VHF two-way radio installed in the cab. The multi-channel antenna for this unit can be elevated to a height of more than 6 meters via a pneumatically-operated aluminum mast that telescopes into the roof of the van’s body.



Complete power supply
and environmental control system

A control desk with a prominent microphone on top

Compact control section houses CCU’s of four TK-44A camera chains

The OB van tows a four-meter long, trailer-housed, diesel-powered alternator, uniquely reverse-mounted, so that it can supply full power even when the van is in motion telecasting special events. The alternator serves all of the electronic equipment and an innovative climate control system that incorporates heating, cooling and automatic dehumidification into a single unit. The alternator trailer also carries a spare tire for the bus.

The integral air conditioning system offers several distinct advantages. It is mounted above the cab in what is normally unused space, thus providing more room in the van’s body for electronic equipment and operating personnel. It is a “ducted” system, so its discharge and return ducts permit a controlled environment, which helps to increase the efficiency of equipment and staff. Distribution of air is regulated via four-way adjustable louvers, eliminating “hot-spots.”

When electric power is not supplied to the van via the alternator or mains, a special auxiliary gasoline, “chill-chaser,” provides temporary interior heat.

Optimum construction advantages

This versatile mobile color television production center illustrates the complete attention the team of engineers from RCA and RTV-Belgrade paid to the station’s OB van requisites. To accommodate RTB’s programming techniques a variety of new concepts were devised. The stability provided by a deluxe, “air-ride” suspension system, and high-flotation tires assure satisfactory performance when the bus must travel over unimproved roads and/or negotiate hilly terrain. The tires are of a wide-based design, measuring 42 x 56 cm, so single-tire tandems, instead of “duals,” are used They can be inflated by means of the van’s self-contained, 12 cu ft [340 litres], quick recovery compressed air facility, which also provides air pressure for the brakes, suspension system, pneumatic mast and maintenance and repair tools

The compact body of the bus is arranged to provide both sufficient storage for equipment and easy access to utility and service panels. Compartments are available to store the camera heads, tripods, viewfinders and lenses, cables and everything else required for immediate operation. Cabling and wiring for equipment is in a central trough below the floor of the bus, while wiring for lights, air conditioning, control and auxiliaries is installed above the ceiling. The exterior roof is steel-plated to allow for camera operation from its surface.

For Yugoslavia … a new dimension of color capability

In summary, this modern, custom-fabricated unit typifies many advances in mobile television service. Now, RTB can schedule a greater variety of television events to keep their public better informed of daily community happenings. As a supplementary benefit, the van can visit neighboring countries and relay aspects of their cultural, entertainment and educational activities back to Belgrade, via the Eurovision and Intravision [sic – Intervision] networks.

With this new degree of telecasting capability, the engineers and staff of Radio-Television Beograd hope to significantly increase their nation’s color television programming, as they bring all of the action, drama and spectacle of sports and other outdoor and remote festivities to their audiences.



For RCA … a continuance of mobile television excellence

Over the years, RCA has produced many mobile broadcasting units for stations and production companies throughout the world. Vehicles have been supplied equipped with monochrome and/or color cameras for telecasting activities that originate either outdoors or in locations away from the studio. Other units have contained video tape machines for direct recording of events as they occur, for immediate or delayed playback. Sometimes cameras and VTR’s are integrated to provide both live and video taped pick-ups. And, supplementary sound trucks or vehicles housing the variety of support systems, power auxiliaries and RF signal transmission facilities are often included.

For the television station manager, the deluxe studio-on-wheels represents an excellent solution to his problem of bringing virtually any locale into the homes of the public. By producing more and belter units, RCA introduces a new level of operational performance and programming creativity to remote telecasts.

RCA extends its special thanks to Messrs. Antic, Mitrovic, Yelacic and Zizic, the engineering directors at RTB responsible for the acquisition of the OB van. They cooperated most completely and cordially in providing many of the facts necessary for the publication of this story.


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