6 May 2023

Television reception issues in Gulgong

Since it began investigating TV reception in Gulgong in October 2014, the ACMA has discovered a number of contributing factors to the problems being experienced by some Gulgong residents.

In September last year, television services from Mount Cenn Cruaich television tower, which covers Gulgong, were moved to an all-VHF configuration as part of the retune. Based on established technical planning assumptions for television, this should have meant that a household with an optimised VHF high-gain antenna, up to 10 metres above ground depending on precise locality, would get adequate reception of all services throughout Gulgong. As the ABC digital service had already been in VHF prior to retune, it was also expected that most households would already have an appropriate antenna installation to receive VHF services.

But since the retune, in response to mounting evidence of widespread TV reception problems in Gulgong, we have learned more about a range of local factors affecting your community.

In particular, we have uncovered an unusually widespread problem with power line interference, which affects many, though not all, households. The ACMA has been working closely with the local electricity supplier, to help resolve these interference issues. From the ACMA’s experience, it usually takes a long time to resolve widespread interference of this type.

We have also monitored the received signal strength in Gulgong over several weeks and learned that television coverage in Gulgong fluctuates over the course of the day. This is most likely because of the great distance to the television tower on Mount Cenn Cruaich. It means a small but significant minority of households in the town are not always able to receive television services from Mount Cenn Cruaich.

We also found some other problems that have been able to be resolved. Some households had faulty masthead amplifiers that were emitting spurious signals and causing interference to their neighbours’ television. As part of this work, we learned that many households in the area simply do not have adequate antenna installations. Some were even relying on UHF aerials only, which meant that following the retune they would have had great difficulties receiving any television service at all.

Finally, we have also become aware that the heritage listing of many parts of Gulgong may impose legal restrictions on viewers in terms of the height of antenna they can install—this is likely to hinder or prevent some households from obtaining an adequate signal even if one is available. A common workaround in areas such as Gulgong, where an antenna of up to 10 metres height would be appropriate, is to install a masthead amplifier on a lower antenna.

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Unfortunately, use of a masthead amplifier increases the vulnerability of viewers to power line interference if this interference is at a high level and at a close location.

Options to improve television receptionThese problems are not cheap or simple to fix and are sufficiently serious that we are now in discussions about them with government, broadcasters, community representatives and the local electricity supplier. Our initial objective is to get as accurate a fix as we can on the problems and identify the range of potential solutions.

At this stage we are analysing two broad options for improving reception in Gulgong:1. A local UHF broadcast (retransmission) site in Gulgong.2. Gulgong to continue to rely on VHF services from Mount Cenn Cruaich (or satellite,

as appropriate) with reception issues addressed by individual households.

Option 1Installing a local UHF broadcast (retransmission) site in Gulgong would provide a single, community-wide solution to the reception problems. However, it is not clear who would fund provision of such a facility or who would take on the role of owning, operating and maintaining the local broadcast site.

The ACMA does not have a role in mandating or in allocating funding for these types of services. The ACMA’s role would be limited to providing assessment of a proposal for the new broadcasting site from the channel planning and licensing perspective. What is lacking is an applicant with the very substantial funds required to establish or run such a facility.

Broadcasters have completed the rollout of infrastructure required for television digitisation and restack. The relevant government programs to assist communities with digital transition are complete. Retransmission services can be provided by third parties on a self-help basis, such as councils, mining companies and local community organisations; however, to date no one has emerged with the willingness or the means to install a retransmission site.

More information about establishing retransmission sites is available from the ACMA website . 1

Option 2Under this option, viewers in Gulgong would continue to rely on VHF services from Mount Cenn Cruaich. Reception issues would be addressed at the individual household level, through the following steps: In areas where adequate and reliable terrestrial television reception is available,

households would be advised to try to optimise their receive antenna installations for fringe VHF reception.

The local electricity supplier would continue to work on resolving power line interfer-ence where it is evident that power line interference is causing reception difficulties and adequate terrestrial television reception would be otherwise available.

Households would be advised to install the Viewer Access Satellite Television (VAST) service in all areas where adequate terrestrial reception is not possible, whether due to inadequate TV signal coverage, antenna height heritage restrictions and/or unresolved power line interference.

1 Information about digital television terrestrial self-help retransmission services are available from www.acma.gov.au/Industry/Broadcast/Spectrum-for-broadcasting/Spectrum-digital-television/digital-television-terrestrial-self-help-retransmission-services or via http://tinyurl.com/mq23sdg.

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Both options are feasible from a technical viewpoint, although both come with costs. The ACMA expresses no view on which option is preferable.

In the meantime, is there anything viewers can do to improve reception?From the ACMA’s experience with other communities which have also been affected by complex reception problems, it may take some time before a final solution is agreed and implemented.

For some viewers who want to try to immediately improve their TV reception, the VAST service may be the best option. The VAST service is intended to provide an alternative to terrestrial digital television services and is an option for individual households who are unable to reliably receive digital television services. This service is not affected by power line interference. Viewers would need to pay for the cost of the VAST equipment and its installation (approximately $700–1,000) but there are no ongoing costs. Viewers of VAST will have access to the full range of free-to-air services that are available terrestrially.

Households who do not wish to go to VAST may choose to try to optimise their antenna system to one suitable for a fringe VHF coverage area. The antenna system that the ACMA would normally recommend for areas such as Gulgong is a single high-gain VHF antenna mounted up to 10 metres above the ground. However, households need to be cautious because while improving their antenna installation would improve reception, the presence of power line interference in parts of Gulgong means that viewers may still experience some reception difficulties—although less often.

Some households may be able to receive alternative coverage from the (UHF) Central Tablelands television tower located at Mt Canobolas. An antenna installer would be able to confirm if households can receive the alternative services. The antenna system that the ACMA would normally recommend for these services is a single high-gain UHF antenna mounted up to 10 metres above the ground. The UHF services are less prone to power line interference.

Where can I get more information?Below is some additional information, including a map of Gulgong that shows areas of poor reception, marginal reception, the heritage conservation area, as well as areas that may be able to receive alternative coverage from Mt Canobolas. There is also guidance for households about what may be causing their reception problems and options to improve their reception. Whilst the map should provide a useful guide, only an experienced antenna installer would be able to provide specific advice for individual households about their best option after measuring the television signal level and quality at each household.

The ACMA published a blog in December 2014 to explain the issues affecting reception in Gulgong and provide affected viewers with relevant information.2 The ACMA’s TV reception information hub also provides information on how to resolve TV reception issues, focusing specifically on the importance of an optimised receive antenna system for reliable TV reception.3

2 The blog is available on the ACMA’s website at www.acma.gov.au/theACMA/engage-blogs/engage-blogs/In-terference/Reception-difficulties-in-Central-Western-Slopes.3 The ACMA’s TV reception information hub can be found at www.acma.gov.au/tvreception.

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The ACMA is also working with the local federal Member of Parliament and other key stakeholders to find the best combination of solutions going forward for the problems uncovered in Gulgong.

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Attachment A—Options for improving TV reception in GulgongPlease note: The coverage map and associated information are indicative only. Call an ex-

perienced antenna installer for the best advice before purchasing or installing reception equipment.

A lower cost solution may become available in the future if a local UHF tower is installed.

Figure 1: Gulgong digital television coverage areas

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Poor coverage areas (red areas)

Households in poor coverage areas (red areas) are unlikely to have adequate VHF coverage over time. These households should consider applying for the Viewer Access Satellite Television (VAST) service.

Marginal coverage areas (orange areas)

Households in marginal coverage areas (orange areas) are unlikely to get adequate reception if they are affected by power line interference. These households should engage an antenna installer to assess if adequate VHF television reception is possible or if VAST is their best alternative.

Alternate coverage areas (green areas)

Households in alternate coverage areas (green areas) may be able to receive adequate reception from the Central Tablelands television tower located at Mt Canobolas. These services use UHF frequencies and are less prone to power line interference. These households should engage an antenna installer to assess if adequate UHF television reception is possible from Mt Canobolas or if VAST is their best alternative.

Heritage conservation area (blue boundary)

Households within the heritage conservation area are not allowed to install a fringe-area VHF antenna at 10 metres above ground level, unless the roof height is 10 metres (double-storey building). Households in these areas should engage an antenna installer to assess if their antenna system can be optimised for fringe-area VHF reception or if VAST is their best alternative.

Other areas Households outside the poor, marginal and heritage conservation areas are expected to get reliable TV reception if they have an optimised fringe-area antenna system with the antenna installed up to 10 metres. Households with an optimised antenna system in these areas are more likely to have adequate immunity to power line interference. The ACMA has found that households that use masthead amplifiers (boosters) are more susceptible to power line interference.

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