Storm damage revives interest in radio

If the recent floods and cyclone taught us anything, it was how reliant we all are on modern technology and personal devices. The widespread power cuts were tolerable, because with luck and a good charge behind us, we still had our phones, and phones could keep us in touch not only with friends and family, but the news, weather and a whole world of other distractions. But when the cell towers went down as well, it was a swift and stark reminder of just how important they have become. Many people were essentially isolated, due mainly to the fact that cell tower back-up batteries could only run for around 48 hours without power.

Brains that had become used to being fully wired were forced to redirect their energy and remember … what was it we used to do? “Listen to the radio,” came the dim and distant answer.

Dusty portable models were dug out of drawers and dialled into life, and entire families trooped out to the car to catch up on news or listen to music in the driveway. However, the situation was also a reminder of why adapting to alternative information and entertainment sources had been so welcome in the first place, as in many local spots, radio reception is far from ideal, with fading signals and crackling interference commonplace. While this is to be expected in remote rural corners tucked behind a ridgeline, one of the worst reception areas has always been, and remains to this day, the region’s biggest service centre – Warkworth.

As many have pondered as their car radio reception slowly fades, surely something can be done to improve matters these days, even allowing for the town’s low-level, riverside location?

Unfortunately not, according to Darrell McNab, who runs Rodney Broadband, an internet provider that uses radio frequencies to connect rural customers to fibre in Warkworth via a network of strategically sited hill-top antenna.

“What happens is that the town is in a radio basin,” he said. “So you’ll drop from Pulham Road, where you’ll get everything from Auckland at full strength, and as you drive down Bertram Street, signal strengths will go down to one tenth of what they were at the top and that goes for everything, FM, AM, the lot.”

FM stations are particularly affected, as their higher frequency soundwaves do not travel as well as AM’s lower frequencies. McNab said trying to propagate, or transmit, FM stations in Warkworth and the surrounding area was particularly challenging, as they generally rely on ‘line of sight’ transmission between antenna, and there were plenty of sharp dips in between.

“Places like Warkworth, the Dome, Matakana Valley, Whangaripo – trying to propagate FM through there is very difficult,” he said.

But surely the radio stations or broadcasting powers could simply install another Warkworth antenna to boost the signal in town? Alas, it is not that simple.

“When you licence an FM station in New Zealand, Radio Spectrum Management (the Ministry of Business, Innovation and Employment department responsible for radio in NZ) will give someone a frequency, but you can’t have two towers in the same area on the same frequency – that simply won’t work, they will interfere with each other,” he said.

McNab said because of this, placement of radio towers was an exact science carried out to optimise the coverage each station could get, and the best spots had long since been located by licence holders.

“It’s the same for cell towers. Mobile phone frequencies are halfway between AM and FM, so coverage does get over hills, but there will be black spots. They only have their frequency or channel, and you can’t have two towers on the same frequency –they have to be out of range from each other.

“So that is a limitation of the technology we’ve got – it’s probably as far as it can go for radio comms.”

McNab said that while the current rollout of wifi calling, which enables phone calls via the internet, would be an asset for keeping in touch, a good old-fashioned radio should always be kept on hand.

“If there’s an absolute emergency and everything goes out, your default is AM radio,” he said. “Make sure you have a radio and plenty of batteries.”

Radios varying in size from pocket portable to heavy-duty tradies’ models can be bought from stores including The Warehouse, Noel Leeming and Mitre 10, as well as online.