Electricians and cablers are in a position to provide an excellent TV signal to home owners. Cosmos Vlahopoulos explains the history of installations and what’s needed in today’s market.

It all started in 1956 with the welcoming lunch of TCN9 in Willoughby, NSW. Analogue in black and white had begun. Channels were added, broadcasting was widened across Australia, and colour TV was introduced in 1975. The biggest step in order to introduce more programs and better quality was the introduction of digital TV.

After identifying the challenges that viewers would face during the transition with many needing old analogue antenna upgrades to digital ready antenna and due to a skill shortage to get it done in the set timeframe with no fall-back to analogue option available, the Australian Government established a Digital Switchover Taskforce to coordinate and oversee the transition to digital from analogue television and delivering the switchover by the end of 2013.

The taskforce commenced producing and publishing and made available through the Australian Building Codes Board (ABCB) a number of handbooks to assist with the analogue to digital switchover.

These were technical handbooks aimed to help with the installation of domestic and multiple dwelling unit (MDU) installations.

After introducing digital TV and having analogue and digital TV channels working in parallel for some time, the decision by the government was made to switch off analogue TV transmissions.

Back in June 2010, the Australian Government announced that a digital dividend of 126MHz of 700MHz band spectrum, comprised of Australian UHF television channels 52 to 69, would be released.

The digital dividend was made possible by the move to digital-only television broadcasting under the Digital Television Switchover program. The final step to releasing the digital dividend was for a significant number of digital television services to be moved to new channels so that channels 52 to 69 could be cleared and made available for new services such as 4G and wireless broadband. The digital dividend channel changes took place, affecting approximately 450 geographic coverage areas across Australia.

While there was a rapidly increasing number of installers migrating to the TV and antenna industry during the switch over time, most of them only worked in the industry for a short period. Several installers had come from other industries, including electricians, but had to give up and turn back to the industries they used to work in as the switchover programme was being completed.

An increasing number of issues appeared that only a properly trained and experienced professional with adequate test equipment could solve.

A program of endorsing installers was implemented, whereby a basic online assessment was conducted to qualify digital-ready installers. The programme was more about inclusiveness to overcome the skill shortages and get the job done in the allocated timeframe.

They had to have a field strength analyser to make the required digital signal levels and quality measurements at the antennas and subsequent TV outlet plates to ensure that there was enough digital TV signal and margin available for uninterrupted reception.

Most of the installers came from the subscription television sector, who conducted their own internal training. Some training modules were also written and included in the Cert 3 Telecommunications qualification.

Have you ever experienced pixelated TV reception or the annoying noise when the sound breaks up while watching TV? If you have, you know how frustrating this can be for anyone, including your customers. If not, you are one of not unlucky ones.

Is terrestrial TV reception still required? Defiantly. While there is an increasing number of streaming services available now, Free-to-air Terrestrial (FTA) TV via an antenna is still the most reliable way of watching FTA TV. Research has identified it as an increasingly reliable source of information for viewers over the years, more so in the regional areas of Australia.

Government departments have recently identified many free-to-air antennae and MATV systems being installed that are not working properly, based on the number of complaints they have received. These departments include the Department of Infrastructure, Transport, Regional Development, Communications, Sports and the Arts and the Minister for Communications, who looks after Communications.

The old analogue TV reception was quite forgiving in the sense that reflected signals arriving at the antenna would result in ghosting (double images) and a weak signal that resulted in a snowy picture. The viewers, however, seemed to put up with it back in the day.

This is not the case in the unforgiving digital TV domain. There is what is known as the digital signal cliff edge. As this threshold is approached and exceeded, the sound screeches, the picture pixelates and very quickly disappears completely.

There are many reasons that the digital signal level and quality measurements are not within specification. These range from poor quality equipment, wrongly selected equipment types, uncompressed or loose connectors, kinks in the coaxial cable and a range of interference signals, for example, the 4G/5G towers, to name a few.

Only a specialist antenna installer with suitable radio frequency (RF) knowledge, experience and appropriate test equipment, such as a spectrum analyser, would be able to diagnose and rectify domestic and MDU reception problems.

There are three main types of measurements required to be done with a calibrated digital signal analyser when installing a TV antenna and TV outlet plates to make sure that there is sufficient margin in the received digital signal for each channel. These are:

1. Signal power level
2. Signal bit error rate (BER pre and post error correction)
3. Signal modulation ratio (MER)

In a Single Dwelling installation, the FTA TV outlet signal levels requirements are Min 45dBµV and the Max is 80dBµV. The minimum required MER is 25dB. The BER needs to be pre <8E-4 and post <2E-7 for optimal reception.

In an MDU installation, the TV signal outlet levels have different levels depending on the number of channels in the system. In general, for a system with greater than 20 RF channels, they would be in the range of 58dBµV to 76dBµV. The required MER is 26dB and the BER needs to be <2E-4 and <2E-7 for optimal FTA TV reception and a MER of 18 for perfect satellite reception.

These signal minimum and maximum measurement requirements are given in the relevant and current Australian Standards, being:

• AS 1367:2023 Coaxial cable and optical fibre systems for the RF distribution of digital television, radio and in-house analogue television signals in single and multiple dwelling installations
• AS 1417:2023 Receiving antennas for radio and television in the VHF and UHF broadcast bands — Design, manufacture and performance of outdoor terrestrial television antennas

To add to the above, there are also constraints around the differential of signal channel levels at different system outlets. These are quite complex measurements, not only to make but also to understand why and what they mean, and only a professional installer can comprehend it all. If you don’t believe me, try reading the relevant standard. It’s a very specialised document.

In many instances, when a consultant’s MDU specification accompanies a tender document, it is quite generic in the sense that it will specify the desired outcome however, very little detail is available as to the type of cabling topology and equipment required to be installed. A (Master Antenna TV) MATV specialist installer is required to design the type of system needed for the building type and choose the values of all the equipment to commission it and make it work properly.

When installing a MATV system or simply an antenna on a single house, the choice of equipment, including the antenna type for the location, is imperative to get the right outcome, and only a specialist installer will know which is the best suited and what to do to install it.

They will take into account the building type, the length of the cable runs and more importantly, their losses at the required TV signal frequencies, any active and passive devices required then carry out calculations to produce a system design that works.

No matter how large or small your project is, play it safe and get a professional specialist to design and install it for you.