Martin Dethridge, studio engineering manager, working in the engineering rack room at Prime News.

Martin Dethridge, studio engineering manager, working in the engineering rack room at Prime News. Photo: Penny Bradfield

It is 1988 and Federal Treasurer Paul Keating is in the government party room at Parliament House explaining to the assembled Labor MPs why the government is going to change the nation's television ownership rules.

As Keating explains it, those Australians who live outside the state capital cities have access to only one commercial TV channel.

Most regional and rural viewers have only ''one bunch of slop'' to watch, Keating tells his parliamentary comrades.

The Prime News on-air presentation control room.

The Prime News on-air presentation control room. Photo: Penny Bradfield

If country viewers want to choose between ''three bunches of slop'', that is their business, he says. They should at least have the choice.

A year later, Australia's first aggregated regional TV market came into effect when the individual TV stations serving Canberra, Wollongong and Orange were forced to compete in a combined southern NSW TV market.

The Hawke government's aggregation policy, reputedly sparked by the sports-mad prime minister's inability to watch AFL matches or interstate races while staying at the Lodge, was the biggest shake-up that Australian television had seen.

Tom White, presentation co-ordinator, in the Prime News on-air presentation control room.

Tom White, presentation co-ordinator, in the Prime News on-air presentation control room. Photo: Penny Bradfield

Fast forward almost 25 years and the TV landscape is being radically transformed again as viewers and broadcasters across the country switch to digital.

And all to give every Australian household the choice of what Keating might describe as 11 bunches of commercial slop - the latest, WIN TV's 24-hour infomercial channel ''Gold'', arrived on screens this week.

The rollout of digital television is the most extensive, expensive and complex change to free-to-air TV since the introduction of colour telly in the 1970s. The federal government is spending almost $400 million to ensure no one loses their TV signal, WIN TV alone has spent almost $30 million on transmitter upgrades across its regional network and hundreds of thousands of old TV sets have been dumped.

And why? Beyond extra channels, sharper pictures and clearer sound, the main benefit of digital is that it is a more efficient use of the broadcast spectrum.

In the same amount of bandwidth that we get, say, ABC1 on analog, we can get the four ABC TV channels plus two radio channels on digital.

Plus digital has long been the world standard for TV production and broadcasting, with the US, Britain and other countries already converted or converting.

Australia's nationwide shutdown of analog signals, which will eventually force every household to invest in digital TV equipment, began in Mildura on June 30, 2010. The region-by-region conversion will be complete when Sydney switches by December 31 next year.

D-day for viewers in Canberra and across southern NSW is Tuesday June 5. The analog signals carrying the region's five original TV channels are scheduled to be turned off at 9am on that day.

Those five channels have been simulcast in digital - partly subsidised by the federal government - for the past few years, as the networks have added digital-only channels such as 7Mate, ABC News 24 and GO!

According to Nerida O'Loughlin, executive director of the Digital Switchover Taskforce set up by the government to oversee the roll-out, the new suite of digital channels has been the ''significant factor'' in driving the take-up of digital technology by viewers. The taskforce's most recent quarterly ''digital tracker'' survey found that 36 per cent of those surveyed saw increased channel choice as the main benefit of digital TV, while 30 per cent cited better picture quality.

The survey estimated that 86 per cent of the 500,000 households across southern NSW and the ACT had already converted at least their main TV set to digital. But that still leaves as many as 70,000 households with only four weeks to switch before the analog signal is cut.

In some rural areas where there has been poor or no analog TV coverage, broadcasters have built new digital transmitters - sometimes referred to as ''gap-filler'' transmitters.

The switch-over has already occurred in some Canberra suburbs, with households in the Conder and Banks area moving to digital-only services last December.

While digital signals in some areas can be prone to picture freezing, pixellation, loss of sound and complete ''blue-screen'' drop-outs, O'Loughlin said the taskforce's help line had received only six calls about reception difficulties in Conder and Banks.

Heavy rain and high wind can affect the quality of digital TV signals, as can a faulty or incorrectly positioned antenna or corrosion of older TV antenna masts and cabling.

''The Canberra region is expected to receive a good digital TV signal,'' O'Loughlin said. ''The Canberra region is well covered by the main transmitters at Black Mountain and Mount Tuggeranong. There are also two smaller transmitters at Weston Creek (which broadcasts ABC and SBS services only) and Conder.''

People with reception difficulties should contact endorsed ACT antenna installers listed at the taskforce's www.digitalready.gov.au website.

For the broadcasters, digital conversion has been a substantial investment.

WIN TV group business director Shirley Brown, the executive in charge of managing the regional network's analog switch-off, said WIN had spent about $27 million nationally, including about $6 million in the ACT and southern NSW.

Ms Brown said 24 ''gap filler'' transmitters had been installed across the region and 47 sites required equipment upgrades.

''The costs are greater than for aggregation because of the simulcast in analog - propping up analog transmitters that are not produced anywhere in the world - and the high cost of running the transmitters, the power usage [being] a major concern,'' she said. ''These high costs are the reason the regional broadcasters had to switch off the analog services sooner than the metropolitan networks because of the large number of transmitters needed to service viewers.''

After June 5 you will be able to watch live free-to-air TV in Canberra only if you've got a digital-enabled television, a digital set-top box or a video recorder with a digital tuner.

The federal government is spending $380 million on a national scheme to ensure households receiving the maximum rate of the age pension, disability support pension, carer payment, Department of Veterans' Affairs service pension or income support supplement don't lose their free TV signal.

The Household Assistance Scheme, administered through Centrelink, provides for the supply and installation of a high-definition digital set-top box, or a new antenna and cabling as required. The scheme came under fire this year when it was reported that the average government installation was costing taxpayers $698 - outrageously expensive when a high-definition digital set-top box retails for less than $100.

The Minister for Broadband, Communications and the Digital Economy, Senator Stephen Conroy, defended the scheme, saying installations could range from $158 for a household in a large regional city to $492 for a set-top box and full antenna upgrade for a household in a ''small country town'' to as much as $1528 for a satellite dish and set-top box in remote outback Queensland.

The other major cost to the community of the digital switch has been environmental.

The switchover taskforce's most recent ''digital tracker'' report found that 27 per cent of households with a digital TV as their main set - or 1,419,000 households - had disposed of their old analog set by throwing it away or taking it to dump.

Only 6 per cent said they had dropped it off for recycling.

This week the government announced that a new national scheme for free recycling of wanted TV sets would begin in the ACT on May 15.

The National Television and Computer Recycling Scheme aims to boost recycling rates for e-waste to 80 per cent by 2021.

Televisions and computers contain valuable non-renewable resources, including gold and other precious metals, as well as toxic materials like lead, bromine, mercury and zinc.

DHL Supply Chain will provide the free recycling service for territory households and small businesses, with collections to begin at the Mugga Lane and Mitchell transfer stations on May 15.

For the federal government, the digital TV switch-over is more than a question of giving viewers re-runs of Get Smart in high-definition widescreen.

The analog spectrum freed up will eventually be carved up and sold off to telecommunications companies to provide the next generation of mobile and internet services.

As much as $4 billion could be raised from the auction of this so-called ''digital dividend''. The government has yet to divulge how it will spend the windfall, which should land in time for the next election.

For the ABC, digital has allowed the national broadcaster to extend the reach and influence of its traditional strengths: children's programming and news.

And, for the commercial networks, their new digital channels have helped staunch the loss of younger viewers, tackle the growth of pay-TV and offer advertisers niche audiences.

Even before June 5, Canberra viewers are increasingly switched on to the new channels.

Year-to-date ratings data shows that, between them, the new generation of digital channels have a bigger share of the prime-time viewing audience (28.3 per cent) than the most-watched main channel, WIN (19.8 per cent).

Prime7 chief executive Doug Edwards said the new channels were not simply cannibalising main channel audiences.

''It's providing viewers with greater choice, and we have seen increases in free-to-air viewing as a result,'' he said.

''For example, changes to legislation now allow us to schedule AFL on a digital channel, so we can deliver four games each week to Canberra on 7Mate, matching what viewers in Melbourne can see.''

About 40 per cent of the current broadcast spectrum will be freed up when all analog TV signals are finally switched off.

This space on the airwaves is considered ideal for a new generation of internet and mobile broadband services via 4G-enabled devices.

With telecos anticipating a 30-fold increase in demand for mobile broadband capacity in coming years, the spectrum vacated by analog TV will be auctioned from November this year for use after January 1, 2015.

Telstra, Optus and Vodafone have expressed interest in bidding.

The Australian Communications and Media Authority will conduct the auction and the government has already capped the amount of spectrum that can be bought by one party to promote competition in the 4G market.

The Royal Bank of Scotland has estimated estimated the auction of the vacated 700MHz and 2.5GHz parts of the spectrum could be worth up to $3.25 billion and $925 million, respectively.