Aging antenna replaced at remote broadcast site

When a major Australian broadcaster identified the need for a replacement antenna at one of its broadcast sites in NSW, its RF engineering team approached ZCG Scalar to discuss a suitable solution.

The antenna being replaced was an RFS 4UD-LP digital television antenna, one of an aging fleet still in service at broadcast sites around Australia. The broadcaster advised ZCG Scalar that there is no direct replacement for the RFS unit currently available, with a significant number of these antennas still in use at broadcast sites across Australia, many having been in service for more than 20 years.

The unit at the remote NSW site had failed due to water ingress. In developing a replacement, ZCG Scalar looked to address this issue directly, rather than simply replicate the existing design.

The project presented ZCG Scalar with a specific set of technical and operational requirements, including compatibility with the existing broadcast infrastructure and feeder system, as well as the physical and environmental demands of an outdoor installation. Following discussions between the two engineering teams, ZCG Scalar’s in-house RF engineering, antenna design and manufacturing capabilities were drawn on to develop a new solution around the broadcaster’s current and future requirements, engineered as a like-for-like replacement for the RFS 4UD-LP.

The result was the Z4UD-520650, a new UHF broadband antenna designed for broadcast applications. In developing the replacement, ZCG Scalar reviewed the antenna’s construction, manufacturing process and component selection to address the water ingress issue identified with the original unit. The resulting design exceeded all requirements, including improved environmental protection for outdoor broadcast applications.

Housed within a robust fibreglass radome, the 2.6 m antenna is rated to withstand wind speeds of up to 160 km/h and features integrated DC grounding, a four-bay dipole array, VSWR of less than 1.2:1, 8 dBd gain, a maximum TV power rating of 2 kW and a 7/8″ EIA flanged connector for straightforward integration with the existing feeder systems. The antenna was designed and manufactured solely at ZCG Scalar’s East Gippsland facility in Lindenow, Victoria, drawing on the company’s in-house RF engineering, design and manufacturing capabilities.

ZCG Scalar first received the enquiry in September 2025. Once the required specifications were confirmed and the project approved, the engineering team completed the design of the Z4UD-520650 in just 11 days before progressing to manufacture. The completed antenna has since been installed at the broadcaster’s remote NSW site and is now operational, providing a locally designed, manufactured and supported replacement for its existing broadcast infrastructure.

For ZCG Scalar, the project reflects the broader value and commitment of maintaining RF engineering, design and manufacturing capability onshore. When aging infrastructure has no direct like-for-like replacement available, having a local team with the capability to engineer a solution around the original requirements means the specification does not have to be compromised. This can make the difference between a straightforward upgrade and a prolonged outage. With many RFS 4UD-LP units still in service nationally, some approaching or exceeding two decades of operation, the Z4UD-520650 provides Australian broadcasters with a locally supported option for replacing aging/legacy infrastructure before failure occurs.

With more than five decades of experience in RF communications, ZCG Scalar continues to support Australian broadcasters and critical communications organisations with locally designed, manufactured and supported RF solutions. The company will be exhibiting at Comms Connect Melbourne from 14–15 October on Stand 65.

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